A Path Analysis of Cognitive, Affective, and Behavioral Predictors of Treatment Response in a Methadone Maintenance Program

Purpose: Continued illicit drug use by opioid-dependent patients maintained on methadone is a serious problem, undermining the goal of methadone maintenance treatment and increasing the risk for HIV. The current study employed structural equation modeling (SEM) to examine cognitive, affective, and behavioral predictors of treatment response during the first 12 weeks of methadone maintenance treatment. Methods: 302 opioid-dependent individuals (72% male; 28% female) entering a methadone maintenance program (MMP) were provided with a comprehensive intake assessment. Heroin and cocaine use were assessed using twice weekly urine toxicology screens. The model accounted for 37 percent of the variance in abstinence from illicit opiates and 38 percent of the variance in abstinence from cocaine. Results: Continued heroin use while maintained on methadone was predicted by pre-treatment severity of addiction and by strength of self-identity as an “addict.” Cocaine use was predicted by pre-treatment severity of addiction, low self-efficacy, lack of negative affect, and strength of self-schema. The strongest predictor of abstinence from both heroin and cocaine was attendance at the adjunctive manual-guided psychosocial group interventions. Implications: Implications for treatment are discussed.