Timing is everything: antiretroviral nonadherence is associated with impairment in time-based prospective memory

Non-adherence to combination antiretroviral therapies (cART) is highly prevalent and significantly increases the risk of adverse HIV disease outcomes. The current study evaluated the hypothesis that prospective memory – a dissociable aspect of episodic memory describing the ability to execute a future intention – plays an important role in successful cART adherence. Seventy-nine individuals with HIV infection who were prescribed at least one antiretroviral medication underwent a comprehensive neuropsychological and neuromedical evaluation prior to completing a one-month observation of their cART adherence as measured by electronic medication monitoring. Non-adherent individuals (n = 31) demonstrated significantly poorer prospective memory functioning as compared to adherent persons (n = 48), particularly on an index of time-based ProM (i.e., elevated loss of time errors). Deficits in time-based prospective memory were independently predictive of cART non-adherence, even after considering the possible influence of established predictors of adherence, such as general cognitive impairment (e.g., retrospective learning and memory) and psychiatric comorbidity (e.g., depression). These findings extend a nascent literature showing that impairment in time-based prospective memory significantly increases the risk of medication non-adherence and therefore may guide the development of novel strategies for intervention