When treatment hurts: antiretroviral side effects moderate the pathways from social support to suicidal ideation among people living with HIV in China.

People living with HIV (PLWH) bear a disproportionate burden of suicidal ideation. This study examined whether social support relates to suicidal ideation through HIV-related stress and depressive symptoms, and whether these pathways differ by antiretroviral therapy (ART)-related side effect status. A cross-sectional survey of 391 PLWH in Zhejiang Province, China, used generalized structural equation modeling (GSEM) to test mediation pathways, estimated separately among participants with and without ART-related side effects. Overall, 23.02% reported suicidal ideation. Social support was not directly associated with suicidal ideation (β = -0.007, p = 0.924) but had indirect effects through HIV-related stress alone (β = -0.020, p < 0.001) and sequentially through HIV-related stress and depressive symptoms (β = -0.013, p < 0.001). Pathway structure differed by side effect status: among those without side effects, only the chain mediation was significant; among those with side effects, HIV-related stress predicted suicidal ideation both directly and indirectly, and prevalence was higher. Between-group differences in path coefficients were not formally tested; subgroup findings are exploratory. Social support was negatively associated with suicidal ideation primarily through indirect mechanisms, with the structure of that risk pathway differing by ART-related side effect status. Differentiated interventions integrating suicide risk screening into HIV care are needed.