Positive memory specificity reduces adolescent vulnerability to depression
Depression is the leading cause of ill health and disability worldwide1. A known risk factor of depression is exposure to early life stress2. Such early stress exposure has been proposed to sensitise the maturing psychophysiological stress system to later life stress3. Activating positive memories dampens acute stress responses with resultant lower cortisol response and improved mood in humans4 and reduced depression-like behaviour in mice5. It is unknown whether recalling positive memories similarly reduces adolescent vulnerability to depression. Here we used path modelling to examine the effects of positive autobiographical memory specificity on later morning cortisol and negative self-cognitions during low mood in adolescents at risk for depression due to early life stress (n = 427, age: 14 years)6. We found that experimentally assessed positive but not negative memory specificity was associated with lower morning cortisol and less negative self-cognitions during low mood one year later. Moderated mediation analyses demonstrated that positive memory specificity reduced later depressive symptoms through lowering negative self-cognitions in response to negative life events reported in the one-year interval. Positive memory specificity actively dampened the negative effect of stressors over time, thereby operating as a resilience factor reducing the risk of subsequent depression7. These findings suggest that developing methods to improve positive memory specificity in at-risk adolescents may counteract vulnerability to depression.