A laboratory model of cocaine withdrawal in humans: intravenous cocaine.

Seven adult intravenous (IV) cocaine users completed a protocol investigating changes in behavior after the self-administration of cocaine. During sessions, the participants could self-administer up to 6 doses of IV cocaine (32 mg/70 kg) twice each day. Both 2- and 3-day binge conditions were tested. At 39 hr after the 3-day but not the 2-day binge of cocaine use, total Beck Depression Inventory scores were increased and participants reported increased ratings of Irritable and decreased ratings of I Want Cocaine. Exposure to stimulus cues associated with IV cocaine increased ratings of I Want Cocaine during periods of abstinence after both 2- and 3-day binges and increased ratings of Depressed only after the 3-day binge of cocaine use. The cessation of binge cocaine use produced modest changes in mood and cocaine craving that were related to the length of the binge and varied as a function of time since last cocaine use. Responsiveness to cocaine cues also varied as a function of the length of the previous cocaine binge.