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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 |
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).
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.
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