In clinical practices and research program we have commonly observed dual diagnoses in patients with serious disorders of alcohol or other substance abuse. One of the most frequently encountered comorbid psychologic disorders is depression. Although depression can be associated with alcohol or substance abuse as an antecedent or a consequence most of the current literature on cocaine appears to focus on depression as a consequence.
Clearly, depression is a known and expected consequence of cocaine withdrawal directly related to the mechanism of action at the presynaptic nerve terminals. However, as previously noted, certain people with severe pre-existing depression may unconsciously use (abuse) cocaine to treat this condition. We have recently encountered two such people.
The first was a 39-year-old man who participated in one of our research studies. He used cocaine intravenously in relation to situational (i.e., reactive) depression. He reported that he had started cocaine use about 6 months earlier because of depression related to a recent divorce and was using up to 8 g (i.e., 30 to 40 injections) daily. He said “I never did street drugs in my life until 6 months ago. … I would never have started if I wasn’t lonely.”
The second was a 30-year-old man who had first started using cocaine at 20 years of age and was injecting himself with about half a gram of cocaine once a month when first seen. Clinical interview and psychometric assessment revealed a history of chronic (apparently endogenous) depression that he had treated periodically with cocaine. Cocaine abuse in this patient was successfully treated with a combination of fluoxetine (Prozac) and intensive psychotherapy. He has now been drug free for over 6 months. (In addition to its use in the treatment of depression fluoxetine (Prozac) may have some direct pharmacologic effect in reducing the self-administration of cocaine.)
Obviously, not all cocaine-dependent patients will have a dual diagnosis. However, for those with comorbid depression, clinicians should consider the possibility that the depression may be a cause rather than a result of cocaine abuse. Hence, treatment of the cocaine abuse without appropriate treatment of the underlying depression may well result in relapse and related sequelae.