Genetic variation of the dopamine transporter (DAT1) influences the acute subjective responses to cocaine in volunteers with cocaine use disorders

OBJECTIVEThe aim of this study was to identify gene variants of DAT1 (SLC6A3) that modulate subjective responses to acute cocaine exposure. METHODSNon-treatment-seeking volunteers (n=66) with cocaine use disorders received a single bolus infusion of saline and cocaine (40 mg, intravenous) in a randomized order. Subjective effects were assessed with visual analog scales administered before (−15 min) and up to 20 min after infusion. Ratings of subjective effects were normalized to baseline, and saline infusion values were subtracted. Data were analyzed using repeated measures analysis of variance. DNA from the participants was genotyped for the DAT1 intron 8 (rs3836790) and 3′-untranslated region (rs28363170) variable number of tandem repeats. RESULTSParticipants were mostly male (∼80%) and African American (∼70%). No differences were found among drug use variables between groups for either polymorphism. Carriers of the 9-allele of the DAT1 3′-untranslated region (9,9 and 9,10) exhibited greater responses to cocaine for ‘high’, ‘any drug effect’, ‘anxious’, and ‘stimulated’ (all P-values