The effect of acceptance and commitment therapy on autobiographical memory, episodic future thinking, and depression in major depressive disorder

Major depressive disorder, in addition to mood problems, along with several cognitive defects, such as weakness in autobiographical memory and episodic future thinking, is an issue that many treatment methods have been used to improve. The present study aims to investigate the effect of acceptance and commitment therapy (ACT) on autobiographical memory, episodic future thinking, and depression in patients with major depressive disorder.

This research was a randomized quasi-experimental design of pre-test, post-test, and follow-up with a three-month interval. A number of 30 people, ranging from 18 to 60 years (22 women and 8 men) were selected using the available sampling method among the clients of the psychiatric clinic of Tehran Institute in 1400 and 1401, following the entry and exit criteria, and selected randomly in two experimental groups (15 people) and control (15 people) were replaced. The study tools included a SCID structured interview to diagnose depression, an autobiographical memory test, episodic future thinking, and a DASS-21 stress-anxiety-depression questionnaire. The experimental group received treatment based on ACT for eight sessions the sessions were individually held once a week for half an hour, and the control group did not receive any training. For data analysis, a mixed intragroup-intergroup analysis of variance test was used by SPSS-26.

The results from the mixed intra-group and inter-group variance analysis revealed that ACT significantly improved autobiographical memory and episodic future thinking (P<0.05). Additionally, ACT was noted to reduce depressive symptoms during both the post-test and follow-up stages in the experimental group, outperforming the control group.

Based on the results of this study, considering the effectiveness of treatment based on ACT and the durability of its effect in the three-month follow-up, this treatment method is recommended for improving cognitive defects such as overgeneralization of autobiographical memory, episodic future thinking, and reducing symptoms of major depression.