The Effects of Psychotherapy for Major Depressive Disorder on Daily Mood and Functioning: A Longitudinal Experience Sampling Study.

Experience sampling methodology (ESM) was used in a randomized controlled trial of short-term therapy to examine changes in daily affect and reactivity to daily event appraisals among depressed patients. Fifty-five depressed adults (mean age 37 years, 80% female) were randomly assigned to one of two therapy conditions. Using an interactive voice response system, participants rated activities and emotional functioning eight times per day for seven days. Thirty-one participants completed treatment and repeated ESM post-treatment. Broad improvements in mood, cognition, and physical functioning were similar across treatment conditions, with the largest improvements for markers of positive affect. Participants demonstrated increased resilience, i.e., diminished reactivity to stressors at post-treatment. Changes in reactivity to positive daily situations were minimal. Findings underscore the utility of ESM in psychotherapy research and the importance of including measures of both positive and negative affect and experiences.