The dual-deficit model of psychostimulant addiction. According to the model, withdrawal from chronic stimulant use leads to decreased synaptic availability of DA and 5-HT that, in turn, contributes to withdrawal symptoms, drug craving, and relapse. DA dysfunction underlies anhedonia and psychomotor disturbances, whereas 5-HT dysfunction causes depressed mood, obsessive thoughts, and lack of impulse control. Protracted withdrawal phenomena are postulated to contribute significantly to relapse...
