Relation Between Executive Function Test Performance and Treatment Outcomes During Brief Psychotherapies for Later-Life Depression

Objectives Executive dysfunction is common in late-life depression (LLD). This study examined whether: (1) executive function predicts change in depressive symptoms during brief psychotherapy and (2) performance on cognitive tests changes during psychotherapy. Design Post hoc analysis of a noninferiority randomized clinical trial comparing 9 weekly sessions of problem-solving therapy (PST) and Engage, a streamlined psychotherapy for depression. Setting Two-site trial at academic medical centers in Seattle, WA and New York, NY. Participants Participants were 150 older adults (68% women) with major depressive disorder, Mini-Mental State Examination [MMSE] ≥ 24, and cognitive test data available for primary analysis. Participants ranged in age from 60-89 years ( M = 70.4, SD = 7.4). Measurements Cognitive measures included the Iowa Gambling Task (IGT), Wisconsin Card Sorting Test (WCST), Stroop test, Digit Span, and Hopkins Verbal Learning Test (HVLT-R). Treatment outcomes consisted of longitudinal assessment using the Hamilton Depression Rating Scale (HAM-D) and World Health Organization Disability Assessment Schedule 2.0(WHODAS). Results Linear mixed effects models showed that baseline executive functioning did not predict improvement in HAM-D scores. Better Stroop performance was associated with improved WHODAS scores. Paired t -tests revealed pre- and post-treatment improvement in executive functioning test performance as measured by the IGT (Total Money subscale; p =0.002) and Stroop test ( p = 0.002) across 9 weeks of both treatments. Conclusions Baseline cognitive functions, including executive function, did not influence reduction in depressive symptoms during brief psychotherapies. Brief psychotherapies may improve aspects of executive function such as decision-making related to reward. ClinicalTrials.gov Identifier NCT02086201