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

## TL;DR

This study found that cognitive function at the start of therapy did not predict depression improvement, but brief psychotherapies improved certain executive functions in older adults with depression.

## Contribution

The study is the first to show that brief psychotherapies can improve executive function in older adults with depression, independent of symptom reduction.

## Key findings

- Baseline executive function did not predict improvement in depressive symptoms during therapy.
- Better Stroop performance was linked to improved disability scores after treatment.
- Participants showed improved performance on the Iowa Gambling Task and Stroop test after therapy.

## Abstract

Executive dysfunction is common in later-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.

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.

Two-site trial at academic medical centers in Seattle, WA and New York, NY.

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 to 89 years (M = 70.4, SD = 7.4).

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).

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.

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.

NCT0208G201.