Substance Use-Related Intentional Nonadherence to Antiretroviral Therapy Among Young Adults Living with HIV.

Antiretroviral therapy (ART) reduces HIV disease burden, increases life expectancy, and prevents HIV transmission. Previous research suggests that believing that it is harmful to take ART when using substances (i.e., interactive toxicity beliefs) leads to intentional ART nonadherence; however, these associations have not been investigated among younger adults living with HIV and have not been linked to clinical outcomes. We examined the associations among interactive toxicity beliefs, intentional nonadherence, and HIV clinical outcomes in young adults living with HIV. People living with HIV younger than the age of 36 years who tested positive for at least one substance use biomarker ( N  = 406) completed a 1-month pretrial run-in study that included computerized interviews, substance use biomarkers, HIV viral load, and unannounced pill counts for ART adherence. Analyses compared three HIV clinical outcome groups: (1) HIV viral unsuppressed, (2) HIV viral suppressed and ART nonadherent, and (3) HIV viral suppressed and ART adherent, on substance use, interactive toxicity beliefs, and substance use-related intentional ART nonadherence. Results showed that a majority of participants reported intentional nonadherence. Participants with unsuppressed HIV reported greater interactive toxicity beliefs and intentional nonadherence. We conclude that intentional nonadherence adds to the detrimental impacts of substance use on ART adherence and interactive toxicity beliefs that foster these behaviors may be amenable to interventions.