Antisocial personality disorder predicts methamphetamine treatment outcomes in homeless, substance-dependent men who have sex with men.

One-hundred-thirty-one homeless, substance-dependent MSM were enrolled in a randomized controlled trial to assess the efficacy of a contingency management (CM) intervention for reducing substance use and increasing healthy behavior. Participants were randomized into conditions that either provided additional rewards for substance abstinence and/or health-promoting/prosocial behaviors ("CM-full"; n=64) or for study compliance and attendance only ("CM-lite"; n=67). The purpose of this secondary analysis was to determine the affect of ASPD status on two primary study outcomes: methamphetamine abstinence, and engagement in prosocial/health-promoting behavior. Analyses revealed that individuals with ASPD provided more methamphetamine-negative urine samples (37.5%) than participants without ASPD (30.6%). When controlling for participant sociodemographics and condition assignment, the magnitude of this predicted difference increases to 10% and reached statistical significance (p<.05). On average, participants with ASPD earned fewer vouchers for health-promoting/prosocial behaviors than participants without ASPD ($10.21 [SD=$7.02] versus $18.38 [SD=$13.60]; p<.01). Participants with ASPD displayed superior methamphetamine abstinence outcomes regardless of CM schedule; even with potentially unlimited positive reinforcement, individuals with ASPD displayed suboptimal outcomes in achieving health-promoting/prosocial behaviors.