Predicting Medication Nonadherence in Older Adults With Difficult-to-Treat Depression in the IRL-GRey Randomized Controlled Trial

Objective: Nonadherence to antidepressants interferes with optimal treatment of late-life depression. This analysis examines clinical and treatment factors pre-dicting medication nonadherence in difficult-to-treat late-life depression.Methods: Secondary analysis of data from a clinical trial of antidepressant pharmacotherapy for Major Depressive Disorder in 468 adults aged 60+ years. All participants received venlafaxine XR for 12 weeks. Nonremitters were ran-domized to augmentation with either aripiprazole or placebo for 12 additional weeks. Medication adherence was assessed 14 times over 24 weeks. The analy-ses examined sociodemographic, clinical, and treatment factors that may pre-dict antidepressant nonadherence during early (weeks 1-6), late (weeks 7 - 12), and augmentation (weeks 13--24) treatment.Results: Poor cognitive function and early response were predictive of early nonadherence. Poor cogni-tive function and prior nonadherence were predictive of late nonadherence. Living alone was associated with nonadherence both late and during augmen-tation treatment.Conclusion: Future studies should consider the role of early response and cognitive function to improve antidepressant adherence, particu-larly among older adults who live alone. (Am J Geriatr Psychiatry 2022; 30:994 - 1002)