Poly-Drug and Marijuana Use Among Adults Who Primarily Used Methamphetamine

This study examines health and legal problems associated with use of commonly reported substances and combinations of substances in a sample of adults with long histories of methamphetamine (meth) use. Data are from a 2009-11 eight-year follow-up interview in an intensive natural history study (N = 373). Respondents who had not used illicit substances in the year preceding the follow-up interview (38%) were compared to users of marijuana-only (16%), meth-only (7%), and poly-drug users who used meth + marijuana but not heroin or cocaine (19%), and poly-drug users who used heroin and/or cocaine (20%). Multinomial regression results indicate that compared to drug-abstinent individuals, greater depressive symptomatology was reported for poly-drug users of meth + marijuana (p = .001), and arrest rates were higher for poly-drug users who used heroin/cocaine (p = .006); no differences in health, mental health, or criminal involvement were observed for meth-only users compared to abstinent individuals. Users of marijuana-only and poly-drug users of heroin/cocaine experienced poorer physical health status than those who were abstinent. To further explore this finding, use of marijuana for medical reasons was examined by drug use group. Overall, health and criminal outcomes varied based on type and combination of substances used, and these differences should be considered when planning treatment strategies.