Elevated central serotonin transporter binding availability in acutely abstinent cocaine-dependent patients.

Abstract

Recent work has underscored the role of serotonergic neurotransmission in chronic neural adaptations to cocaine dependence. The authors tested for evidence of serotonergic dysfunction during acute abstinence from cocaine, a period of high risk for relapse in cocaine dependence. Binding availability of dopamine transporters and serotonin transporters was measured in 15 cocaine-dependent subjects during acute abstinence and in 37 healthy comparison subjects by using [(123)I]beta-CIT and single photon emission computed tomography. Significant increases in diencephalic and brainstem serotonin transporter binding (16.7% and 31.6%, respectively) were observed in cocaine-dependent subjects. Brainstem serotonin transporter binding was significantly inversely correlated with age across diagnostic groups. These findings provide further evidence of serotonergic dysfunction during acute abstinence from chronic cocaine use. Age-related decline in brainstem serotonin transporter binding may underlie the poor response to selective serotonin reuptake inhibitor antidepressants seen in some elderly depressed patients.