The Information-Motivation-Behavioral Skills (IMB) model of antiretroviral therapy (ART) adherence describes self-reported ART adherence determinants among people living with HIV (PLWH) who struggle to achieve optimal adherence, but less is known about young Black gay, bisexual, and other men who have sex with men (MSM), a group reported to have less than optimal ART adherence levels, partially affected by depression. Using the IMB model, we analyzed baseline data from 315 Black MSM living with HIV aged 18-34 years struggling with ART adherence enrolled in a multi-state mobile health (mHealth) randomized controlled trial. Generalized structural equation modeling was used to estimate the direct and indirect effects of (1) ART-related information, (2) motivation and (3) behavioral skills, or treatment self-efficacy, on non-optimal self-reported ART adherence (<
80%, Wilson's adherence measure). Prevalence of non-optimal ART adherence was 28.3%. Low behavioral skills were directly associated with non-optimal ART adherence (β = 0.69, SE = 0.10, p <
.001). Low behavioral skills significantly mediated the relationship between low motivation and non-optimal ART adherence (Sobel z = 4.12, p <
.001). Low information was not associated with treatment self-efficacy. Low motivation had a greater overall effect on non-optimal ART adherence among those with none/mild depressive symptomatology (β = 0.30, SE = 0.13, p <
.001), and the direct effect of low motivation on non-optimal adherence was null among those with moderate/severe depressive symptomatology. Development of combination HIV prevention interventions designed to improve ART adherence should combine culturally appropriate mental health care into HIV treatment that go beyond social support among those who may be experiencing depressive symptomatology.