Project Khanya: Peer-Delivered Intervention to Improve HIV Medication Adherence and Substance Use in South Africa

Inclusion Criteria: * HIV positive and on ART * ≥18 years of age * At least moderate substance use risk in the past 3 months for at least one non-tobacco substance (measured by the WHO- ASSIST: score ≥11 for alcohol, ≥4 for non-tobacco drugs) * ART nonadherence and/or risk of virologic failure, defined as at least one of the following in the past 12 months 1) re-engaging in care after ≥1 month of being out of care (confirmed by pharmacy refill data) 2) ≥1 episodes of VL \>400 copies/mL 3) on second- or third-line ARTs. Exclusion Criteria: * Severe risk/likely dependence for opiates (WHO ASSIST score \>26) because opiate substitution therapy is largely not available * Severe alcohol dependence symptoms that may warrant medical management of potential withdrawal symptoms/stabilization prior to study participation * Inability to provide informed consent or complete study procedures in isiXhosa or English * In third trimester of pregnancy during baseline * Currently enrolled in another study or treatment program focused on substance use (including Matrix) or ART adherence. * Untreated or undertreated major mental illness that would interfere with study procedures