The effect of involuntary positive memory retrieval on mood repair of non-clinically depressed people

Previous studies have demonstrated that voluntary positive memory retrieval commonly leads to mood repair in the non-depressed population but not in depressed people, while it has been suggested that involuntary positive memory retrieval can repair the mood of depressed people. However, the difference in the mood repair effect between voluntary and involuntary positive memory retrieval on depressed people remains unclear from an experimental perspective, and thus, we examined this difference in a laboratory setting. After inducing negative mood in non-clinical participants with high and low depressive tendency (n = 48), they were asked to conduct a voluntary memory retrieval task or sound location task inducing involuntary memory retrieval. In this retrieval phase, participants retrieved memories of positive pictures that had been encoded in the laboratory. The results demonstrated that involuntary positive memory retrieval caused a more positive change in the mood of people with high depressive tendency compared to voluntary retrieval. These results suggest that involuntary positive memory retrieval contributes to the repair of depression.