Cocaine-induced psychosis.

BACKGROUND: Chronic stimulant use can produce a paranoid psychosis that is similar to acute paranoid schizophrenia. While this phenomenon has been systematically explored in amphetamine abusers, it has been relatively unexplored in a systematic fashion in cocaine abusers.
METHOD: The experience of cocaine-induced psychosis was evaluated in 55 individuals consecutively admitted for treatment of DSM-III-R cocaine dependence. Each subject was interviewed about their experiences of psychosis while intoxicated by means of a standardized, semistructured interview.
RESULTS: Fifty-three percent (29/55) of those interviewed reported experiencing transient cocaine-induced psychosis. There was no significant difference in lifetime amount of cocaine use or amount of cocaine use in the month before admission between those who experienced psychosis and those who did not. The psychosis-positive group used significantly more cocaine in the year prior to admission (p less than or equal to .02) and had a longer duration of use (p less than or equal to .01). Males were significantly (p less than or equal to .05) more likely than females to develop psychosis. Ninety percent (26/29) developed paranoid delusions directly related to drug use. Ninety-six percent (28/29) of the subjects experienced hallucinations: 83% (24/29), auditory hallucinations; 38% (11/29), visual hallucinations; and 21% (6/29), tactile hallucinations. Twenty-seven percent (15/55) of subjects developed transient behavioral stereotypies.
CONCLUSION: Cocaine-induced paranoia is a common experience among chronic users. Amount and duration of use are related to its development. Implications for a kindling model of cocaine-induced psychosis will be discussed.