The Self Medication Hypothesis

A focus on:

 

Chronic Cocaine Abuse

&

Attention Deficit Hyperactivity Disorder

 

 

(A Literature Review)

Daniela Plume, B.A.  April 10, 1995

 

 

Forward by the author, Sept. 22, 2002

Self Medication was not a theory commonly accepted in 1995, and less still, in Canada. I had hoped to explore the ‘possible’ relationship between drug abuse and undiagnosed underlying pathologies as an honors thesis. However, in my final year of my BA., I was hard pressed to find any courses that interested me. I approached one of my professors to obtain permission to explore this topic on my own. There was some skepticism as to whether a theory specific to cocaine abuse and ADHD could even be supported.

To my surprise and delight, many researchers had been exploring the possible correlations between chronic substance abusers and their drugs of choice with underlying pathologies.

This study marks the first time all of the known research was compiled and presented in one cohesive document.

I never did return to University after leaving the honors program during a difficult pregnancy.  Three children and many years later, I started a successful karaoke company in Ottawa, On. Canada with my partner in life. I cannot imagine a better application for a psych degree.

Daniela Plume
DOG & PONY Sound
©

 

Introduction

 

Historically, drug and alcohol dependencies have been attributed to sin, disease, maladaptive, self destructive, and antisocial behavioral patterns.  Addicted substance abusers have frequently been charged with poor motivation, lack of insight, escapism, and the development of self destructive tendencies.  Khantzian (1985a) asserts these allegations stem from archaic models of therapy and rigid attitudes as to which paradigm best justifies substance abuse and subsequent treatment modalities.  Many clinicians still hold that psychotropic medication for coexisting pathology should not be administered until the patient has attained abstinence for at least one year.  However, coexisting disorders should be addressed concurrently, not ignored until abstinence has been consolidated (Weiss & Colins, 1992; Zweben & Smith, 1989).

       Various studies have indicated a high degree of coexisting psychopathology amongst both adolescent and adult substance abusers.  The most frequently seen include affective disorders (Dilsaver, 1987; Gawin & Ellinwood, Jr., 1988; Weiss, Mirin, Michael, & Sollogub, 1986), borderline personality disorder (Blume, 1989; Bukstein et al., Brent & Kaminer, 1989), antisocial personality disorder (Kleinman, Miller, Millman, Woody, Todd, Kemp, & Lipton, 1990), depression (Dorus & Senay, 1984; Kleinman et al., 1990; Lemere & Smith, 1990), anxiety disorders (Bukstein, 1989; Weiss & Rosenburg, 1985), conduct disorder (Dimilio, 1989; Milin, Halikas, Meller, & Morse, 1991), and attention-deficit hyperactivity disorder (Carroll & Rounsaville, 1993; Dimilio, 1989; Milin et al., 1991; Wilens, Biederman, Mick, & Faraone, 1995).

          Given the prevalence of comorbid psychopathy in substance abusers observed in both clinical and treatment settings, Khantzian (1985b) postulated a theoretical model of self medication; a concept first raised by Freud (1884) upon noting anti-depressant properties of cocaine.

 

The Self Medication Hypothesis - Brief Overview

 

       On the basis of psychodynamic/psychiatric diagnostic findings and clinical observations, Khantzian (1985b) proposed a model of self medication as an etiological factor in substance abuse.  He suggested psychotropic drug effects interact with psychiatric disturbances and “painful affect states” to predispose some individuals to addictive disorders.  The addict’s choice of drug is thought to be the result of the interaction between the psychopharmacologic properties of the drug and the “primary feeling states” experienced.  In this way, the drug effect is thought to substitute for defective or non-existent ego mechanisms of defense (Khantzian, 1985b).  A number of clinical findings have supported the hypothesis that the preference for a specific drug is not random, but rather, appears to be a process of “self selection” (Dorus & Senay, 1980; Khantzian & Treece, 1985; Rounsaville, Weissman, Crits-Cristoph, Wilbur, & Kleber, 1982; Weissman, Slobetz, & Prusoff, 1976; Wurmser, 1974; and others).  This course of self selection has also been referred to as “preferential drug use” (Milkman & Frosch, 1973) and “the drug of choice” phenomenon (Wieder & Kaplan, 1969).

 

Cocaine Abuse: The Self Medication Hypothesis

      

       Cocaine is thought to help overcome fatigue and alleviate depression in some depressed individuals (Freud, 1884; Schnoll, Daghestani, & Hansen, 1984; Khantzian, 1975), increase feelings of self esteem, assertiveness, and frustration tolerance (Weider & Kaplan, 1969), overcome boredom and emptiness (Wurmser, 1974), and alleviate impulsive/hyperactive states in attention-deficit disordered individuals (Weiss, & Mirin, 1986; Zweben & Smith, 1989, and others).  Cyclical mood disorders (manic depressive illness, cyclothymic disorders) have been shown to be more common in cocaine abusers than opiate addicts (20 %  vs 1%), suggesting such persons may preferentially select stimulants over other illicit substances of abuse (Gawin & Ellinwood, Jr., 1988).  Cocaine is a CNS stimulant with pharmacological properties similar to the stimulant medications Ritalin®, Cylert®, and Dexedrine®  that are commonly used to treat attention-deficit hyperactivity disorder.  Thus, it is thought that individuals with untreated ADHD may be using cocaine to “self medicate” these disease symptoms (Hallowell & Ratey, 1994; Milin, 1995; Weiss, et al., 1986).

 

Sub-Types of Cocaine Abusers

      On the basis of clinical observations, Khantzian (1984; Khantzian & Khantzian, 1984) proposed four categories or “subtypes” to explain how psychiatric/psychological factors might predispose an individual to become and remain dependent on cocaine.  These include pre-existent chronic depression (dysthymic disorder), cocaine abstinence depression, hyperactive/restless/emotional lability syndromes, or attention-deficit disorder, and cyclothymic or bipolar illness.  Other researchers have also speculated that individuals with chronic depression may value the euphorigenic effects of cocaine, whereas cyclothymic and bipolar disordered patients may use cocaine to maintain a hypomanic state and fend off depression (Lemere & Smith, 1990).  Interestingly, individuals with ADHD frequently report a paradoxically placid response to cocaine as well as temporary relief from hyperactive symptoms (Cocores, Davies, Mueller, & Gold, 1987; Gawin & Kleber, 1986; Hallowell & Ratey, 1994; Khantzian, 1984; Weiss & Mirin, 1986; Zweben & Smith 1989).

       Psychiatric disorders, particularly the affective disorders, are believed to increase susceptibility to stimulant abuse (Gawin & Kleber, 1986).  In two unrelated studies, Weiss, et al., (1986) and Gawin and Kleber (1986), each reported 50% of inpatient cocaine abusers to have met the diagnostic criteria for mood disorders.  A number of researchers have also noted patients with attention deficit disorders to be over-represented among those undergoing treatment for cocaine abuse (Cavanagh, Clifford, & Gregory., 1989; Khantzian, 1985b; Milin et al., 1991).

 

Attention-Deficit Hyperactivity Disorder (ADHD)

 & Cocaine Abuse

      

Attention-Deficit Hyperactivity Disorder (ADHD)

Epidemiology

       Incidences of ADHD in adults have not been recognized until recently.  In 1978, Leopold Bellack chaired a conference which focused on adult forms of ADHD, known then as “minimal brain dysfunction”.  It would take more than 10 years before the clinical significance of ADHD in adulthood would be established (Hallowell & Ratey, 1994).  It had previously been assumed that children outgrew ADHD symptoms by adolescence.  Recent studies, however, have reported that upwards to 50-60% of children with ADHD continue to experience residual or full blown manifestations of this disorder in later life (Biederman, Faraone, Spencer, Wilens, Norman, et al., 1993; Gittleman, Mannuzza, Shenker, & Bonagur, 1985; Weiss & Hechtman, 1986).  In one such study, over 70% of children with ADHD were found to have met criteria for the disorder in adolescence (Barkley et al., 1990).  ADHD has also been shown to be more prevalent in males than females by ratios ranging from 2:1 for general populations, to 9:1 for clinics (Biederman et al., 1993; Kaplan & Sadock, 1991).  ADHD is seen across a wide range of cultures, although the incidence rates vary.  This is thought to reflect differing diagnostic practices (American Psychiatric Association, 1994).  There is also some evidence that ADHD occurs more frequently in lower socioeconomic groups (Biederman et al., 1993).

 

 

Diagnostic Criteria

 

       In accordance with the DSM-IV diagnostic criteria (APA, 1994), behavioral manifestations of ADHD must be seen before the age of 7 and must clearly interfere with social and academic functioning (and in later life, occupational functioning).  Previously, ADHD was considered to be a single disorder comprised of three main components:  short attention span, impulsivity, and hyperactivity.  A diagnosis of ADHD required meeting 8 of 14 criteria, such as, fails to listen, interrupts frequently, and fidgets or moves excessively (Kaplan & Sadock, 1991).  The terms “minimal brain dysfunction”, “learning disabilities”, “hyperkinetic syndrome”, and “hyperactivity” have all been used to reflect this pattern of overactivity, short attention span, and learning problems (Ralph & Barr, 1989).  The symptoms described in the DSM-III-R represented behaviors believed by many to be common to children in general, thus, the DSM-IV has returned to an earlier subgrouping system for ADHD diagnosis; separating those children with both attentional deficits and hyperactivity (Davison & Neale, 1994 p.429).

 

       The DSM-IV presently recognizes three distinct classifications of ADHD, with a clear delineation between ADHD combined type (requiring 6 of 9 criterion to be met in both the inattention and the hyperactivity/impulsivity categories), ADHD-Predominantly Inattentive Type (which requires 6 of 9 criterion to be met in the inattentive category and less than 6 for hyperactivity), and ADHD-Predominantly Hyperactive Type (which requires 6 of 9 criterion to be met for the hyperactivity category and less than 6 for inattention).  As a requisite to diagnosis for all three of these categories, behavior must persist for at least 6 months (APA, 1994).

Genetic Factors

       ADHD appears to have a strong genetic component and is seen more frequently in first degree biological relatives (APA, 1994; Kaplan & Sadock, 1991).  Goodman and Stevenson (1989) found concordance for clinically diagnosed hyperactivity in 51% of identical twins and 33% of fraternal twins.  Adoption studies have also shown strong support for a genetic constituent (Morrison & Stewart, 1973; Wender, Reimherr, &, Wood, 1981).

Diathesis-Stress Theory & Outcome Studies

        Weiss, Minde, and Werry (1971) conducted a 5 year prospective follow-up study of 91 subjects aged 10-18 years.  They found adolescents with ADHD tended to have lower self esteem, and most continued to be distractible, impulsive, and emotionally immature when compared with controls matched for age, sex, IQ, and social class.  The results of this study suggest three main “outcomes” of childhood ADHD:  individuals with ADHD who function normally in adulthood, individuals who as adults continue to have problems with concentration, irrationality, anxiety, and who experience general difficulties in work and personal life (most fall into this group), and those who develop serious psychiatric and/or antisocial pathology, and may experience extreme depression, suicidal tendencies, become heavily involved with drugs and/or alcohol, and exhibit antisocial behavior.  Outcome studies may aid in explaining why many individuals with ADHD are successful in later adult life and conversely, why all individuals with ADHD do not develop substance abuse problems.  Research has strongly suggested that children with both attentional deficits and hyperactivity (combined type) are most at risk to develop conduct problems, oppositional behavior, and other severe problems in later life (Barkely, DuPaul, & McMurray, 1990).

 

       Bettleheim (1973) proposed a diathesis-stress theory to explain the development of ADHD; suggesting that certain critical factors impinge on a child’s life, which may in turn become a catalyst for the development of ADHD in those genetically predisposed.  Studies employing multivariate stepwise regression techniques have identified a number of factors thought to predict adult outcome of children with ADHD (Hechtman, 1991; Hechtman, Weiss, Perlman, & Amsel, 1984).  These potential predictors include:  factors specific to the individual child (health, temperament, intelligence, and psychological factors), characteristics of the family (socioeconomic status, emotional/psychological, and family composition), and the larger social environment.  All three of these areas have been shown to contribute significantly to a child’s resiliency/vulnerability.

 

       Children with fewer health problems either during pregnancy, perinatelly, or during infancy, are shown to be less likely to develop ADHD (Hechtman et al., 1984).  Individual characteristics of the child may also influence outcome, as IQ and temperament contribute to the development of quality relationships with others.  Bettleheim (1973) posited temperamental differences between child and parents as one possible stressor which may promote the development of the disorder in a predisposed child.  A hyperactive child may also elicit negative reactions from his/her parents and in turn become more disruptive. Weiss et al., (1971) found children with higher IQs and lower scores of hyperactivity to be more adaptable, socially responsive, and able to elicit positive responses from their environment.  Having an internal locus of control, a good sense of autonomy, and positive self esteem have also been shown to contribute to resiliency.  Generally, the better the ego strengths, the less likelihood of developing ADHD (Ralph & Barr, 1989).  Khantzian (1984, 1985a) emphasized the importance of ego development as a major contributor in predisposing individuals to self medicating for uncomfortable or painful feeling states.

 

       Werner and Smith (1982) found resilient children to come from homes that were more cohesive and supportive, with more structure, regularity, supervision, and clearly defined rules, as well as realistic expectations of the child.  Socioeconomic status appears to be another strong predictor of ADHD in adolescents (Loney, Kramer, & Milich, 1981).  Higher family social status enables greater physical, social, and educational benefits; whereas lower status may place undue stress on both the child and the family.  Finally, the larger social and physical environment can provide a beneficial extra-familial support system through school and church as extended family (Werner & Smith, 1982; Rutter, 1979).  In one long term prospective follow-up study of young adults with ADHD, when asked what had been most beneficial to them while growing up, the most common answer was having someone in their lives who believed in them (Weiss & Hechtman, 1986).

 

 

Comorbid Disorders

       ADHD is usually characterized by impulsivity, lack of emotional control, attentional deficits, and learning disabilities, however, there may be no single critical attribute of ADHD (Wender, 1979).  In fact, many researchers have identified the most frequently seen characteristics of individuals with ADHD to be irritability, emotional lability, explosive personality, violent dyscontrol, depression, low self esteem, anxiety, and aggression (Hallowell & Ratey, 1994; Kaplan & Sadock, 1991; Ralph & Barr, 1989; Turnquist, Frances, Rosenfeld, & Mobrak, 1983; Wender et al., 1981).  In one study, depression was seen to be the most common symptom associated with ADHD (Heussy, Cohen, Blair, & Rood, 1979), while Weiss and Mirin (1986) identified frequent occurrences of borderline personality and antisocial personality disorders.

 

       ADHD in childhood is associated with an increased frequency of psychopathology in later life (Wender, et al., 1981).  Adults are seen to exhibit the same patterns as children with respect to psychiatric and cognitive features, as well as psychiatric comorbidity.  In childhood, ADHD frequently occurs with conduct disorder, antisocial personality disorder, oppositional defiance disorder, and Tourette’s syndrome (APA, 1994).  Researchers have consistently found higher rates of antisocial personality, conduct, oppositional defiant, substance use, and anxiety disorders in adults with ADHD when compared to non-ADHD adults (Biederman et al., 1993; Carroll & Rounsaville, 1993).  In one study, Gittleman et al., (1985) found conduct disorders in 48% of adolescents with ADHD, in 13% of adolescents who had outgrown ADHD, and in only 8% of controls without the disorder.  In another study, Hinshaw (1987) reported a 30%-90% overlap between ADHD and conduct disorder.  Incidences of major depression and anxiety disorders in childhood (which often persist into adulthood) have been documented as well (Hechtman et al., 1984).

 

       Adoption studies have indicated genetic origins associated with an increased risk of substance use, antisocial personality, and somatoform disorders in later adult life (APA, 1994; Morrison & Stewart, 1973; Cantwell, 1975).  Higher rates of affective disorders have been noted in first degree relatives of cocaine abusers (Weiss & Mirin, 1986).  Some studies have observed as much as 25% of children with family pathology to have significantly higher ratings of antisocial and aggressive behaviors (Hinshaw, 1987; Weiss, 1986).  The existence of psychopathology in the family of origin then, appears to be a significant risk factor for substance abuse.

        A significant number of attentional disordered individuals have shown serious delinquent and psychological outcomes, and have been shown to be at risk for chemical dependence (Clopton, Weddige, Contreras, Fliszar & Arrendondo, 1993; DeMilio, 1989, Gittelman, Mannuzza, Shenker, & Bonagur, 1985; Milin et al., 1991; Wilens, et al., 1995).  One study reported a lifetime prevalence of between 15% - 18% for the substance use disorders, making them the “most common mental disorders in the general public, especially amongst males” (Robins, Helzer, Weissman, Orvaschel, Gruenberg, Burke, & Reiger, 1984).  Finally, Milin et al., (1991) noted the severity of substance abusing behavior to be greater in the presence of a coexistent psychiatric disorder.

       Hechtman, Weiss, and Perlman (1984) compared a clinical group of 75 subjects (male and female) who had been diagnosed in childhood as hyperactive, with 44 matched controls in a ten year prospective follow-up study.  They found a tendency for adolescents with ADHD to have greater drug use (75% vs 5%), and were more likely to have experienced a period of dependency or abuse during the five years preceding evaluation.  This difference was seen to level out over the year following the study, perhaps indicating the attainment of similar levels of moral development.  Gittleman and colleagues (1985) studied 101 adolescent males aged 16-23 years.  They found substance abuse disorders in 28% of patients with ADHD, 8% of ADHD children who no longer showed symptoms in adolescence, and in only 3% of controls who had never exhibited ADHD symptoms.


Cocaine Abuse

 A Brief History and Epidemiology

       In the 1890’s cocaine was considered safe. Use escalated but then abated as serious problems were noted.  This pattern was repeated in the 1920’s, early 1950’s, and again in the late 1960’s.  Believing cocaine to be non-addictive, millions of people tried it and abuse exploded.  In fact, the Diagnostic and Statistical Manual of Mental Disorders did not recognize cocaine as an addictive substance until the DSM-III-R was released in 1980 (Kaplan & Sadock, 1992).  In 1974 it was estimated that 5.4 million Americans had tried cocaine; in 1982 this figured had risen to 21.6 million.  By 1985, the National Institute on Drug Abuse estimated 5.8 million Americans abused cocaine regularly.  This figure dropped in 1988, to an estimated 2.9 million abusers and a reported 1.6 million in 1990, with males out-numbering female users 2:1 (Kaplan & Sadock, 1992).

ADHD in Cocaine Abusing Population

       The relationship between cocaine dependence and attention-deficit hyperactivity disorder was first considered by Khantzian (1979) to be the possible extension or “augmentation” of a hyperactive, restless lifestyle by a select group of cocaine users.  In recent years, ADHD has been frequently reported in cocaine abusing populations (Cavanagh, et al., 1989; Gawin, Riordan, & Kleber, 1985; Khantzian, 1983; Rounsaville et al., 1982; Weiss, Pope, & Mirin, 1985).  Carroll and Rounsaville (1993) found 103 of 298 (35%) treatment seeking cocaine addicts to have met the DSM-III-R criteria for ADHD.  In an assessment of 111 juvenile delinquents aged 11-17 years, Milin and colleagues (1991) found attention-deficit disorder with hyperactivity in 23% of the substance abusers and in no cases of the non-substance abusing sample; with 50% of the adolescents with ADHD indicating a preference for cocaine.

Characteristics of Substance Abusers with ADHD

Cocaine abusers with ADHD tend to be younger at the time of first treatment, and report more severe and frequent substance use, earlier onset of cocaine abuse, and more previous treatment attempts (Carroll & Rounsaville, 1993).   In one study, hyperactive adolescents were seen to be significantly younger than controls when they started, at the point of heaviest use, and when they stopped using cocaine (Hechtman, Weiss, & Perlman, 1984).  Incidences of ADHD within treatment settings have also been observed to be greater for male than female patients (Everett, Schaffer, & Parsons, 1988).  Carroll and Rounsaville (1993) reported 78% male vs 23% female attentional disordered treatment seeking cocaine abusers in one treatment study, and a similar ratio, 73% male vs 27% female was reported by Gawin and Kleber (1985a).

       In work with chemically dependent adolescents, Ralph and Barr (1989) identified “explosive volatility” as a feature of ADHD behavior not usually included in the clinical description.  Individuals with ADHD in substance abuse treatment settings are often seen to be defiant, argumentative, verbally aggressive, and often verging on premature discharge from treatment facilities.  This apparent escalation of negative behaviors in patients with ADHD, is often attributed to their having limited ego skills and resources to cope with life stressors, as well as the additional stress placed on them by a highly structured inpatient treatment setting (Ralph & Barr, 1989).                                                                                                                       

       In studies comparing adolescents treated for ADHD with stimulant medications and adolescents without ADHD, treatment for ADHD was seen to decrease the risk for future adult drug and alcohol use (Beck, Langford, MacKay, & Sum, 1975; Loney, Kramer, & Milich, 1981;  Henker, Whalen, Bugental, & Barker, 1981).  Adolescents appropriately treated for ADHD showed similar, and in some cases, less incidences of substance abuse than controls.  Fewer studies comparing treated vs untreated individuals with ADHD have been conducted.  In one such study however, Kramer, Loney, & Whaley-Klahn (1981) found untreated hyperactive boys tended towards greater drug use than those properly treated for ADHD.

Diagnostic Issues:

Retrospective Diagnoses & Confounding Variables

      The diagnostic criteria for ADHD in adults requires a history of childhood ADHD; therefore, one major problem in determining the incidence of ADHD in adults is retrospective diagnosis.  Ward, Wender, and Reimherr (1993) recently constructed the Wender-Utah rating scale (WURS) “in an attempt to surmount this problem of retrospectively establishing the childhood diagnosis of ADHD in adults.”  A “cutoff” score of 36 or higher on the 61 item rating scale has been shown to accurately distinguish 96% of individuals with ADHD from controls.  The Utah criteria for ADHD includes items of impulsivity, over-excitability, temper outbursts, affective lability, stress intolerance, and disorganization.  Wender’s diagnostic criteria for adults with ADHD requires:  a childhood history of attention deficits and hyperactivity with one of the following:  problems in school, over-excitability, and temper outbursts, or an adult history of attention deficits and hyperactivity together with two of the following:  affective lability, explosive temper, stress intolerance, disorganization, and impulsivity.  Individuals meeting other diagnoses such as  schizophrenia, depressions, and borderline personality disorders, were excluded from test development studies.

 

ADHD, Antisocial Personality Disorder, & Conduct Disorder:

The Confounding Triad

       The DSM does not purport closed or fixed categories.  Indeed, ADHD itself does not appear to be a mutually exclusive category and has been seen to overlap significantly with oppositional defiant and conduct disorders (Demilio, 1989;  Loney, 1988;  Milin, et al., 1991; Ralph & Barr, 1989).  Ward et al., (1993) found several of the borderline personality disorder symptoms (affective lability, volatile temper, and impulsivity) to overlap with ADHD as well.  It would appear that although the DSM and the Wender-Utah rating scale overlap, they may not necessarily target the same behaviors.  For instance, the DSM does not acknowledge emotional lability and volatile temper as components of ADHD, although many research studies have reported these characteristics (Morrison, et al., 1973).  As well, the Utah criteria does not recognize ADHD without hyperactivity in its diagnosis.

       There is considerable disagreement as to what constitutes the different diagnostic categories.  Some researchers suggest hyperactivity and aggression are separate independent diagnostic categories (Halikas, Meller, Morse, & Lyttle, 1990; Loney, 1988);  some feel they are intertwined (Faraone, Biederman, Keenan, & Tsuang, 1991; Printz, Connor, & Wilson, 1981), and others feel they are essentially the same thing (Quay, 1979).

       There has also been considerable disagreement as to which of the disorders is more likely to induce or contribute to later substance abuse problems.  In substance abusing samples, ADHD was found in conjunction with conduct disorder and antisocial personality disorder (Carroll & Rounsaville, 1993; Gittleman et al., 1985).  Some researchers maintain that aggression or sociopathy, and not ADHD, is related to substance abuse (Halikas et al., 1990).  However, Carroll and Rounsaville (1991) found a high incidence of ADHD in cocaine abusers that was not accounted for by sociopathy.  They also found notably more intense and earlier onset of cocaine abuse, irrespective of comorbidity with antisocial personality disorder.  Finally, in a recent unpublished study, Wilens, Biederman, Mick, and Faraone (1995) found ADHD by itself significantly increased the risk for substance use disorders in adults, and even more so when compounded with antisocial, mood, and anxiety disorders.

Causal Relationship between

 Substance Abuse and Psychopathology

       There is a difference between pre-existing (possibly predisposing) personality disorders and coexistent disorders, or those which may result out of the addiction itself.   Meyer (1986) proposed five possible relationships between substance abuse and psychopathology:  the psychiatric disorder alters the course of substance abuse, substance abuse alters the course of the psychiatric disorder, psychiatric symptoms develop as a result of substance abuse, psychopathology as a risk factor for substance abuse, and substance abuse and psychopathology both originating from a common vulnerability.  Additionally, Bukstein et al., (1989) suggest psychiatric disorders may contribute nonspecifically to the severity and course of substance abuse by reducing treatment compliance.

       The issue of causality has been raised by many researchers who have questioned the relationship between ADHD, anti-social personality, conduct disorder, and substance abuse disorders.  Weiss and Mirin (1986) suggest cocaine may be both a trigger for psychological disorders and a form of self medication for them.  Cocores et al., (1987) propose that ADHD may be reactivated by cocaine.  Dackis and Gold (1985) hold that heavy cocaine use leads to neurotransmitter changes and decreased dopamine secretion that may in turn, be mistaken for a depressive disorder.  Still others suggest self medication and genetic predisposition as two additional possible explanations for the correlation between substance abuse and psychopathology (Milin et al., 1991).

       A substantial number of adults presenting with ADHD symptoms may also experience antisocial personality and conduct disorders as a residual of childhood ADHD.  Gittleman et al., (1985) showed substance abuse to be more prevalent in adolescents diagnosed as hyperactive in childhood.  Moreover, these researchers found conduct disorder to have developed either before, or in conjunction with the onset of substance abuse.

       Depression, anxiety, and aggression have all been observed to occur frequently in individuals with ADHD.  Hechtman et al., (1984) proposed that the incidences of lower self esteem and depression frequently seen in follow-up studies of adolescents with ADHD, may be the result of repeat frustrations at home and school.  Loney (1988) found high rates of aggression amongst ADHD adolescents, which she feels may predispose them to experimentation with drugs as the major reason for their over-representation in substance abuse samples.  Anxiety, depression, and aggression (often associated with ADHD, adolescence, and substance abuse), have all been seen to frequently occur prior to the onset of substance abuse and related problems (APA, 1994).  In a review of longitudinal studies of high school and college boys, Kandel (1978) also found that many of the behaviors and psychological symptoms previously thought to be a result of drug use, actually predated drug use.

              Chemical dependency typically involves a noticeable decline in achievement motivation, as well as depressive and impulsive behaviors. These behaviors largely subside with the cessation of substance abusing behavior.  The diagnosis of ADHD in chemical dependency presents a particular challenge, as ADHD symptomology includes impulsiveness, inattention, and overactivity, and therefore may be under-diagnosed if these symptoms are attributed to the chemical dependency alone (Ralph & Barr, 1989).

       Other diagnostic categories may also invite confusion.  For instance, chemically dependent individuals with severe ADHD in conjunction with oppositional features may be mistaken as having bipolar disorder (Casat, 1982; Cocores, Patel, Gold, & Pottash, 1987; Ralph & Barr, 1989).  Dr. Edward Hallowell (1994) a psychiatrist specializing in ADHD (who has also been diagnosed with the disorder) has noted a tendency for individuals with ADHD to often be incorrectly diagnosed as manic depressive.  This he feels, is due to the tendency for individuals with ADHD to sometimes exhibit highly agitated behaviors which can be followed by a depressive period.  Mania however, can be distinguished from highly active ADHD behaviors, by the sheer intensity of the manic episode and the “pressured speech” which is commonly associated with the manic phase of bipolar illness. Furthermore, lithium, commonly used with bipolar illness, does not help those with ADHD.  Many individuals with ADHD may also be incorrectly diagnosed with borderline, conduct, antisocial personality, and oppositional defiance disorders.  These individuals may meet the “technical requirements” for such diagnoses, but respond favorably to treatments specific to ADHD (Hallowell & Ratey, 1994).  Confusion is also possible with schizophrenic disorders, as adolescents with ADHD may exhibit a rapid, impulsive, poorly organized thinking style typical of schizophrenoform disorders.  Finally, ADHD may also be mistaken for anxiety disorders that occur frequently during adolescence (Ralph & Barr, 1989).

       Stofflymayr, Benishek, Humphries, Lee, and Mavis (1989) agree that many chemically dependent persons meet criteria for more than one psychiatric diagnosis and that dual diagnosis indicates poorer prognosis, however, they feel these findings do not justify the inference that the additional psychiatric diagnosis caused the addiction problem.  They feel instead, that patients ranking high in psychiatric problems also function poorly in many other areas of life; they have a poor prognosis even without the additional psychiatric diagnosis.

Non-Specific Confounding Variables:

The 3rd Variable Problem

     

       The issues surrounding the question of whether ADHD causes, potentiates, or predisposes to substance abuse, particularly cocaine abuse, is still under investigation. Compounding this query are the differing diagnostic measures used and the comorbidity of other psychopathologic diagnoses in conjunction with ADHD and substance abuse (as previously discussed).  A further quandary, is the possibility of the third variable, a factor unrelated to both ADHD and substance abuse that may influence outcome.  For instance, a treatment seeking bias may exist making those presenting for treatment different somehow from non-treatment seeking individuals.  Lower social status, seen more frequently in ADHD populations (Biederman et al., 1993) may contribute nonspecifically to both ADHD and substance abuse.  Gender appears to have a strong relationship to both ADHD and substance abuse, with more males than females seen in treatment programs for substance abuse, and males out numbering females in incidence rates for ADHD.  A number of studies have also indicated age to be a possible contributing factor as well.  Adolescents with ADHD are commonly seen to use drugs and alcohol earlier than non-ADHD adolescents.  In one study comparing juvenile delinquent adolescents, Milin et al., (1991) found non-substance abusers to have the oldest mean age for first use of substances and also the least pathology.  Carroll and Rounsaville (1993) found 25.3 years to be the mean age for treatment-seeking cocaine addicts with ADHD and 28.5 years for those without ADHD.  These researchers also observed ADHD to be more common in white cocaine abusers, indicating that race and ethnicity may also be important contributing factors as well.

       Finally, personal characteristics or individual temperamental traits may contribute to the development of ADHD and substance abusing behavior.  Many factors seen in conjunction with ADHD, such as thrill-seeking behaviors, a need for high levels (and in some cases lower levels) of stimulation, or an individual’s inability to cope with stress may play an important role in the connection between ADHD and cocaine abuse.

Methodological Issues

       There has been a tendency for earlier investigators to indicate there is little or no increased risk for individuals with ADHD to develop later substance abuse disorders.  Loney (1988) noted that many of these studies typically looked at young people ranging from 9 to 23 years.  This age difference may actually reflect the different developmental stages of the individuals within the sample itself.  Furthermore, the age range makes it difficult to generalize from these samples, as few subjects were actually old enough to be exposed to a full range of drugs or to generate a pattern of serious abuse.  In one study, 33 of 95 adolescents with ADHD had tried marijuana with only 70 knowing of someone who used marijuana, and only 50 individuals reporting ever having the opportunity to smoke it (Hechtman et al., 1984).

       These earlier studies were concerned with establishing the long term effects of stimulant medications on individuals with ADHD.  They frequently compared adolescents treated for ADHD to adolescents without the disorder.  Those individuals who received stimulant medications as treatment for childhood ADHD were found to have similar or less incidences of subsequent substance use than controls (Henker, et al., 1981).  Some researchers have suggested of these findings, that ADHD was not found to be a risk factor for later substance abuse (Weiss & Hechtman, 1992).  To make this assertion however, it is necessary to examine both treated and untreated individuals with ADHD.

       Often, studies using hospitalized substance abusers have based their findings on assessments made soon after admission.  Bukstein et al., (1989) consider the timing of diagnosis to be crucial in determining whether psychiatric symptoms were produced by the substance abuse or preceded them.  These researchers also note that the assessment of ADHD relies exclusively on retroactive studies, and are therefore limited by the lack of appropriate control or comparison groups, and also by the reliance on one’s memory of childhood and adolescence.

      

Criticisms of the Self Medication Hypothesis

       Dackis and Gold (1984, 1985) assert that depression in cocaine addicts is a direct result of abstinence symptomology encouraging increased cocaine use, which in turn results in alterations in brain chemistry (dopamine depletion).  They conclude that the addiction itself is the cause of painful emotional states.  There is however, sufficient evidence suggesting that many psychopathologies, including depression, occur prior to substance abusing behavior, especially in childhood diagnosed ADHD.  While this model addresses the potent euphorogenic properties of cocaine and its powerful reinforcing effects (both negative and positive), it does not explain the paradoxical calming effect of cocaine on individuals with ADHD.

       Cocores et al., (1987) also advance a dopamine deficiency hypothesis to better account for the correlation between ADHD and chronic cocaine abuse.  Cocaine is believed to deplete dopamine in already dopamine compromised individuals.  The resultant dopamine deficiency may then induce a temporary and reversible ADHD (even in those without a history of ADHD).  There appears, however, to be more evidence suggesting ADHD predisposes to substance abuse, rather than is reactivated by cocaine, as ADHD has been shown to persevere in more than half of all adults with this childhood diagnosis.  Cocores and colleagues (1987) hypothesized that since patients with ADHD respond to dopamine agonists such as those used to treat ADHD, bromocriptine might also reduce cocaine cravings, as it too is a dopamine agonist.  They report one subject’s restlessness and concentration to have improved after two days and another patient to have shown a “marked improvement” by the third day of bromocriptine trials.  However, this study left many unanswered questions such as:  What is “marked improvement”?  Did the medication in fact reduce cocaine cravings?  What happened after the initial 2-3 days of treatment?  Did bromocriptine effectively treat the ADHD symptoms, and finally, did the patients successfully achieve abstinence?   Cavanagh et al., (1989) employed a double-blind research design to test the effectiveness of bromocriptine.  While the typical response to stimulant medication used in treating individuals with ADHD does in fact suggest an underlying dopaminergic activity (Wender, 1979), the use of the dopamine receptor agonist bromocriptine was not found to be effective (Cavanagh et al., 1989).

       There has been some concern that the stimulant medications used in treating ADHD causes or exacerbates subsequent substance abuse (particularly cocaine and stimulant abuse).  However, there is no evidence supporting this notion, and a number of studies have indicated the opposite - that properly medicated, individuals with ADHD have a reduced risk of future substance abuse (Beck et al., 1975; Loney et al., 1981; Henker et al., 1981).  In fact, 10 and 15 year follow-up studies of adolescents with ADHD showed no significant differences between appropriately medicated adolescents and controls for incidence of substance abuse (Hechtman, Weiss, Perlman et al., 1984; Hechtman & Weiss, 1986).

       Crowley (1984) advocates non-pharmacologic-behavioral modification treatments for substance abuse.  In one study, he reported treating 67 outpatients with 32 individuals agreeing to a contingency contract. Crowley reported that over 90% remained abstinent and in treatment at a 3 month follow-up.  As further evidence of the success of this treatment, Crowley stated “one of our rather successful patients reported having used 45g/week pure cocaine diverted from medical sources.”  However, it is unclear as to what constitutes “success”.  Contrary to the reported success of this study, half of Crowley’s patients were found to have relapsed following the completion of the 3 month treatment/contract (Crowley, 1982; Kleber & Gawin, 1984a).  52% of Crowley’s sample (35 of 67) refused to take part in the contract portion and instead were treated with psychotherapy.  Of these 35 who declined the contingency contracts, 90% dropped out or relapsed within 2-4 weeks.  Kleber and Gawin (1984a) raised questions as to the ethical nature of Crowley’s study as it was based entirely on negative reinforcement.  The therapist held a letter, written in advance by the participant, with the understanding that it would be mailed if the participant relapsed or missed a urine screening.  The letter contained information that would cause irrevocable life-altering consequences, such as an admission of substance abuse to an employer or professional licensing board.

       Clopton, et al., (1993) declared patients with personality disorders to be just as likely to maintain abstinence and complete aftercare programs for substance abuse than patients without personality disorders.  Of  91 patients (18 with personality disorder, 24 with traits of personality disorder, and 49 with no personality disorder), 27 did not complete the initial first phase.  Of the 64 who completed both the inpatient and aftercare programs, 38 (59%) maintained abstinence while 26 (41%) did not. These investigators found no significant differences between those who were in the personality disordered group and the no-personality disorder group.  The results of this study however, are inconclusive, as patients were retrospectively and arbitrarily grouped into three indistinct categories, leaving it unclear as to what personality disorders where considered.  Further, There is no data available for the 27 individuals who did not complete the first phase and subsequently did not participate in the aftercare program.  These individuals may have differed somehow from those remaining in treatment.

More on the Self Medication Hypothesis,

ADHD, & Chronic Cocaine Abuse

       Khantzian (1986) asserts that the nature/nurture, psychology vs biology arguments can work effectively together.  He proposes a self medication hypothesis as a potentially useful heuristic tool for further understanding substance abuse and dependence.  Khantzian’s theory of self medication, the notion that individuals choose specific psychoactive substances to alleviate painful feelings, has been based entirely on non-blind, non-placebo, clinical observations.  Empirical support comes instead from laboratory studies, surveys and biological models which have shown cocaine to increase the activity of dopamine and norepinephrine in the central nervous system (Weiss, et al., 1986).  Milkman and Frosch (1973) provided early evidence that stimulant abusers and narcotic addicts preferentially sought the effects of amphetamines and opiates respectively, to augment “preferred models of adaptation”.  Finally, several researchers have found cocaine abusers with ADHD to exhibit many of the characteristics first identified in early observational case studies.

Case Studies

       Many of the patients treated by Khantzian reported histories of psychopathology which predated their cocaine and other substance use.  Some of these patients expressed how cocaine helped them to “overcome their anergia, become mobilized, and able to perform tasks” (Khantzian, Gawin, Kleber & Riordan, 1984).  A number of patients also reported how cocaine had a paradoxically calming effect on them.  Khantzian worked with one patient who presented a childhood history suggestive of ADHD and who’s chronic cocaine abuse was clearly endangering her life (2 oz intravenous cocaine per week).  Her ADHD symptoms were treated with the stimulant medication methlyphenidate (Ritalin ®).  This patient was presented two years after her initial treatment as the case of  “Mrs. B.” (Khantzian, Gawin, Kleber, & Riordan, 1984).  This case was first presented as a one year follow-up report (Khantzian, 1983).  In the following case studies, the stabilizing properties of methylphenidate were observed over time while patients were in a doctor’s care and/or in a hospital/treatment setting.

1.    Mrs. B  began abusing amphetamines in the eighth grade.  She had been prescribed methlyphenidate in her early twenties (for depression) and reported feeling productive and well. She had refrained from abusing all substances during this period.  When her therapy ended, methylphenidate was discontinued and she reverted back to her previous amphetamine, and then later, cocaine abuse.  Khantzian started her on 15 mg of methlyphenidate 3 times a day while still toxic after a 6 day cocaine binge that had ended only 5 hours prior to her therapy appointment.  Within 24 hours, she began to experience normal sleep and appetite, and her mood was reported to have improved significantly.  Most striking was the disappearance of cocaine cravings.  She experienced one minor relapse in the first year and continued weekly therapy sessions.  At the time of Khantzian’s report (Khantzian et al., 1984) she had not used cocaine in over 2 years.  Her ulcers were reported to have healed, her blood pressure and pulse remained normal, and urine screens had been consistently negative for cocaine and its principle metabolite benzaylecgonine.

2.    Mr. Y. suffered from cocaine abuse as well as obsessive and compulsive behaviors (Khantzian et al., 1984).  He reported using 1/2 g cocaine daily plus weekly binges.  Although he had been participating in an out-patient treatment program for 18 months, he continued to increase his cocaine use.  Khantzian started him on 15 mg of methylphenidate 3 times daily, but lowered this dose at the patient’s request, as he did not like the “high” he was experiencing at the higher dose.  He was then switched to 10 mg every 2 hours.  From the first day of treatment, he reported feeling more calm, relaxed, and purposeful.  He stopped craving cocaine, lost his obsession with pornography and gambling, and at the time of Khantzian’s report, had been abstinent from cocaine for 2 years.  Family reports corroborated his discontinuation of cocaine as well as his appropriate use of medication.

3.    Mr. A. (Khantzian et al. 1984) was treated by Gawin, Kleber, and Riordan (the four researchers then shared their results).  Mr. A. met the DSM-III criteria for ADHD.  He had a volatile temper, low frustration tolerance, and was prone to heated and impulsive arguments which frequently resulted in physical violence.  He reported that cocaine enabled him to feel “normal”;  facilitating impulse control, decreasing anxiety, increasing the organization of thoughts, and providing a sedation effect.  Mr. A. preferred to use cocaine alone and reported using cocaine in anticipation of stressful events.  He had five previous attempts at treatment, all unsuccessful, and was unable to remain cocaine-free even during the 24 hours before testing.  He was started on methlyphenidate and within 3 days experienced an alleviation of ADHD symptoms as well as cocaine cravings.  Although he experienced slight gastrointestinal discomfort, this decreased over the next five days.  During the first week of treatment, his cocaine use decreased from 10 grams per week to 2.5 grams (he had missed one methlyphenidate dose and stayed up too late on another day, both of these days he resorted to using cocaine with friends).  A fifth daily dose of methlyphenidate was added and his cocaine use decreased to 1.5 grams during the second week.  He then requested that he be allowed to double his dose on evenings that he socialized to help him resist cocaine use with his friends.  He was raised to 60 mg/day 2 days week and 50 mg/day the remainder of week.  At the time of this report, he was cocaine free for over two years (verified by urine testing and family reports) and had gained successful employment.

 

       Weiss, Pope, and Mirin (1985) presented 2 additional case studies of individuals with chronic cocaine abuse and ADHD symptoms.  Both individuals reported that cocaine facilitated concentration and helped them to control impulsive behavior and thoughts.  All previous forms of medication and therapy had failed.  Both were put on pemoline, experienced relief from ADHD symptoms, and the desire to use cocaine;  neither were found to have abused their medication.

 

4.    Mr. A’s hospital records and family interviews strongly indicated a childhood history of ADHD.  All previous attempts at treatment for cocaine abuse had failed (including hospitalization 2 months previously) where he had relapsed within only 1 week of discharge.  At the time that he was observed by Weiss and colleagues, he had been free of drugs for 4 weeks and was undergoing treatment in their inpatient drug treatment unit, but showed virtually no improvement and continued to “crave” cocaine.  Mr. A. was almost prematurely discharged from the in-patient program because he was considered to be thoroughly disruptive and was thought to be “untreatable” by staff.  A trial of magnesium pemoline (cylert ®) was started at 75 mg/day.  Within days he showed improvements in concentration and appearance and his desire for cocaine vanished.  When the dose was raised to 112.5 mg, he experienced racing thoughts and insomnia.  He was stabilized at 75 mg/daily and discharged 2 weeks later.  He remained on pemoline for 8 months, cocaine free, with little desire for cocaine.  After 6 months, he again experienced racing thoughts and requested a lower dosage.  At the time of these author’s report, he had been taking 37.5 mg/daily without abuse and had secured gainful employment (Weiss, Pope, & Mirin, 1985).

5.    Ms. B. had a 10 year history of poly-drug use with a primary preference for cocaine, which she used (4 grams/daily) for 2 years prior to admission to the treatment hospital.  Her childhood history and prior hospital records were suggestive of ADHD.  During a 5 week intensive inpatient treatment program she showed no improvement and was started on pemoline.  Within 2 weeks she reported a decrease in cocaine craving.  At a 16 month follow-up, she continued to have little desire to use cocaine.  Although it was frequently available, she had only used cocaine twice.  In an attempt to taper off pemoline she experienced a cocaine relapse.  At the time of this report, she had successfully tapered and discontinued pemoline, and had returned to college where she was experiencing success and abstaining from cocaine use (Weiss, Pope, & Mirin, 1985).

       Turnquist, Rosenfeld, and Mobarak (1983) reported an earlier case of an individual with ADHD and severe alcohol dependency, antisocial personality, poor work and social history, and a history of poor treatment compliance.  He was reported to have used 2-3 pints of rum daily for 7 years prior to treatment.  He was discharged from a previous treatment program for disruptive behavior after only 2 weeks and immediately resumed drinking.  Upon re-admittance to the treatment hospital, he again faced discharge within only 2 weeks.  As he met the DSM-III diagnosis for ADHD, he was placed on a trial of pemoline 37.5 mg/daily.  Within 3 weeks, he experienced improved concentration, felt calmer, less restless, had fewer emotional outbursts, and was able to participate in therapy.  Neurological testing was done both before and after the 4 week program.  Before the pemoline trial, he “became frustrated, exploded into a tirade, and ran from the testing room”.  During the second testing (after pemoline treatment) his concentration, cognitive functioning, and frustration tolerance were all seen to have improved.  He remained in treatment for 6 weeks, and at a 13 month follow-up, was still abstaining from alcohol and taking medication regularly.

       Khantzian (1984) asserts the “normalizing effects of methylphenidate” observed in clinical conditions requires further clinical study.  Although supportive of the various attempts by behavioral, supportive, and psychodynamic treatment approaches, Gawin and Kleber (1984b) assert that all three approaches are necessary when dealing with cocaine abusers, especially when the needs of the individual cocaine abuser are taken into account at the time of treatment seeking. 

      


The Duel Diagnosis:  ADHD & Substance Abuse

      

       Few Canadian substance abuse treatment programs address comorbid psychiatric problems in a comprehensive manner (Milin, 1995).  Comorbid disorders not easily distinguished may be underdiagnosed and therefore untreated.  ADHD is one disorder that is commonly overlooked, misdiagnosed, or ignored (Cavanagh, 1989; Hallowell & Ratey, 1995; Milin, 1995).  Carroll and Rounsaville’s (1993) study illustrates this point:  In a 1 year follow-up interview, not one of the cocaine addicts diagnosed with ADHD the year previously had received any form of pharmacologic treatment during that year, even though about half of them had reported periods of abstinence from cocaine during that time.  The poorer outcome of individuals with ADHD clearly illustrates the consequences of failing identification and treatment of residual symptoms of ADHD in cocaine users.  Psychiatric evaluation for residual attention-deficit disorder is essential as patients with this disorder have been seen to require specialized treatment (Gawin & Ellinwood, 1988; Zweben & Smith, 1989).

         

       Medication can often make the difference between completing or not completing drug treatment programs.  Ralph and Barr (1989) found 70%-80% of individuals with ADHD show an improved response to stimulant medication when compared to controls on placebo. These researchers maintain that therapeutic doses of stimulant medications for individuals with ADHD do not produce euphoria, but rather, enhance behavior.  Zweben and Smith (1989) have noted that in some chemical dependence treatment settings and among some practitioners, all-or-none thinking about medications exist such as:  “never use benzodiazepines with recovering alcoholics” or “never give psychoactive substances to psychoactive substance abusers”.  These kinds of thinking can impede the proper treatment of ADHD in cocaine addicts.  Treatment of ADHD symptoms has been shown to improve self-control and decrease impulsivity, emotional lability, and anxiety;  enabling the patient to become more actively involved in substance abuse rehabilitation therapies (Zweben & Smith, 1989; Khantzian, 1983, 1984).  Cavanagh (1989) and Turnquist (1983) both assert that the symptoms of ADHD compromise the quality of sobriety and may also render such individuals at particularly high risk for relapse due to their “innate discomfort”.  An attitudinal shift towards a medical problem (as opposed to a moral one) may further aid in alleviating depression and improving self-esteem through the reduction of guilt and blame (Turnquist et al., 1993).

       Careful diagnosis is extremely important, as some individuals may attempt to present these symptoms in the hope of obtaining methlyphenidate or other stimulant drugs.  Yet, at the same time, clinicians must take care not to let preconceived notions interfere with their ability to provide treatment planning that is responsive to the patient’s unique needs (Zweben & Smith, 1989).  Blume (1989) intimates the importance of considering the stage of illness or recovery.  Diagnosis should be considered as tentative while patients are still under the influence of substances, experiencing withdrawal or denial, and in early recovery.  From a treatment perspective however, there are benefits to earlier identification and treatment (McKenna & Ross, 1994).  The development of instruments or questionnaires can aid in identifying comorbid illness at initial assessment instead of having to wait the requisite 4-6 week abstinent period as is common practice in many treatment settings.

       Although methylphenidate is an abusable substance, its advantages include medical dispensation through controlled dosages, decreased legal risk, economic stabilization, and the breaking of street associations and secondary abuse reinforcers (Kleber & Gawin, 1984b).  The half-life for cocaine euphoria is less than 45 minutes, with binges characterized by re-administration up to every 10 minutes (Gawin & Ellinwood, Jr., 1988).  Cocaine addicted individuals may stabilize on methlyphenidate due to its longer half-life, as typically, amphetamine plasma half-life is 4-8 times longer than that of cocaine.  Oral administration also provides slower, more consistent elevation of catecholamines, and a slower decline in stimulant levels which may eliminate the euphoric rush associated with the more rapidly absorbed cocaine, and may also attenuate desire for frequent re-administration (Khantzian, Gawin, Kleber, & Riordan, 1984).  Wender et al., (1981)  propose the use of pemoline over methlyphenidate for treatment of ADHD in substance abusers, as it has a longer onset and duration of action and is therefore less likely to be abused.  Positive responses to pemoline are similar to that of ritalin.  However, some patients respond negatively, with reports of increased agitation and decreased concentration.  For these individuals, ritalin or dexidrine may be more beneficial.  A number of researchers feel that since the symptoms that appear to sustain cocaine use are reduced by conventional pharmacologic treatment, such treatments may also facilitate abstinence in self-medicating patients (Gawin & Kleber, 1986;  McKenna & Ross, 1994).

Ritalin® Abuse Concerns

      

          Haglund and Howerton (1982) reported an instance of ritalin abuse amongst opium addicts in one methadone treatment program.  This has been the only report of abuse in the research literature, and was thought to have occurred due to inadequate urine screening procedures.  Ritalin abuse has not been reported in cocaine addicts.  In fact, cocaine addicts with ADHD have tended to show no interest in abusing these stimulant medications (perhaps indicating an extinction of the need to self medicate) and cocaine addicts without ADHD were found to dislike the “high” these medications produce, thought to be due in part to the slower onset of action (Gawin & Kleber, 1985b).   An alternative explanation for reports of ritalin abuse amongst heroin addicts, may lie in the effects of the painkiller Pentazocine (talwin) in combination with ritalin -  known on the street as “T’s & R’s”.  This drug combination has been reported by some addicts as producing an inexpensive opiate effect.

       Leigh and Barrett (1981) found d-amphetamine, methlyphenidate, and cocaine to all produce quantitatively and qualitatively similar effects.  In animal studies, following chronic administration of d-amphetamine, tolerance to all three drugs was seen, indicating a cross tolerance.  Given the possibility for cross tolerance, Kleber and Gawin (1984) suggested methlyphenidate might then lessen the effect of cocaine abuse similar to high-dose methadone maintenance (which causes longer term tolerance to opiates, thereby reducing heroin-induced euphoria and abuse).  Gawin, Riordan, and Kleber (1985) tested the effects of methlyphenidate on 5 cocaine abusers without ADHD and found it did not facilitate cocaine abstinence.  These patients showed a brief positive effect, then the medication appeared to have become ineffective.  Methlyphenidate appeared to have produced a cross tolerance in these patients, as cocaine use increased in parallel with the increasing methylphenidate dosage.  Studies of the combined use of cocaine and stimulant medications have not indicted significant adverse or detrimental effects (Khantzian et al., 1984).  Finally, there have recently been media reports of ritalin abuse amongst adolescent populations in the United States.  Ritalin is apparently being used, not for its stimulant properties, but for its tolerance properties observed.  These adolescents report ritalin enables them to consume larger amounts of alcohol over a longer period of time.

       Crowley (1984) raises legal and ethical concerns about dose escalation, as well as the possibility of patients obtaining concurrent prescriptions from several doctors.  Khantzian (1984) felt it was necessary to weigh the possibility of dose escalation and long term consumption against the consuming addiction.  He felt his patients were extreme cases and ritalin was prescribed for the target symptoms of ADHD.  In this way, the administration of ritalin (a schedule II substance in the United States, athough not a restricted substance in Canada) is both legal and ethical, even when the patient is a substance abuser.

       Clampit and Pirkle (1983) suggest strict parental control, locked medicine cabinets, weekly pill counting, and the use of pemoline over methylphenidate as “risk-free” methods of preventing abuse by adolescents on stimulant medications.  Schatzberg and Cole (1987) offer the following guidelines for administration of stimulant medications to patients with a history of substance abuse:

       1.  when the stimulant drug has clearly been used to improve functioning rather than produce euphoria or to get high

       2.  when a good therapeutic alliance is available

       3.  when the medication can be closely monitored

       4.  when other approaches have failed

       5.  when patient’s problems seriously interfere with life functioning.


Conclusions

       The etiology of cocaine abuse and ADHD is not clear.  What is currently known is that individuals with ADHD often show paradoxical reactions to both cocaine and stimulant medications, and a significant percentage of individuals with chronic cocaine abuse patterns suffer from ADHD and may be self medicating.  Contrary to what had been thought previously, symptoms of ADHD appear to have more impact on the development of cocaine dependence than antisocial personality disorder and other comorbid illness associated with both substance abuse or ADHD (Wilens, et al., 1995).

       Symptom severity, psychiatric diagnosis, and poor response to traditional substance abuse treatments have all been found to predict treatment outcomes of patients with substance abuse disorders.  Osher and Kofoed (1989) feel clinicians have a responsibility to define, develop, implement, and scientifically evaluate programs for the dually diagnosed patient.  Therapies specific to cocaine may be educational, psychodynamic, supportive, and behavioral; but the first goal of treatment should be to interrupt the recurrent binges or daily use of cocaine and to overcome drug craving (Karan, Haller, & Schnoll, 1991 p140; Khantzian, 1988).  There have been frequent reports of stimulant medications removing or reducing cocaine cravings in individuals.  This is thought by many to result out of the removal of painful feeling states, thereby reducing the need to self medicate.  However, the exact mechanisms by which this appears to work is not as yet, understood.  Although chronic cocaine abusers with ADHD are unlikely to discontinue cocaine use immediately following stimulant treatment, proper treatment of ADHD symptoms may enable such individuals to benefit from the therapeutic experience.


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