Selective sensitization to the psychosis-inducing effects of cocaine: a possible marker for addiction relapse vulnerability?

Patients in inpatient rehabilitation for uncomplicated cocaine dependence were asked whether, compared with the time of their first regular use, they could now identify changes in the effects of similar doses of cocaine. We asked about a spectrum of cocaine effects "then" and "now" and whether the same amount of drug caused effects to occur to about the same degree, less intensely (tolerance), or more intensely (sensitization). Nearly half our sample developed predominantly paranoid psychoses in the context of cocaine use. Sensitization was consistently linked only to psychosis-related cocaine effects. It has been proposed that mesolimbic dopaminergic sensitization might contribute to addiction severity. A preliminary followup of patients who were sensitized or nonsensitized to psychosis development suggests that rehospitalization for treatment of addiction may be more frequent in the sensitized group.