Abstract
Depression is the leading cause of ill health and disability worldwide. A known risk factor of depression is exposure to early life stress. Such early stress exposure has been proposed to sensitise the maturing psychophysiological stress system to later life stress. Activating positive memories dampens acute stress responses with resultant lower cortisol response and improved mood in humans and reduced depression-like behaviour in mice. It is unknown whether recalling positive memories similarly reduces adolescent vulnerability to depression through lower cortisol and less negative self-cognitions during low mood. Here we used path modelling to examine the effects of positive 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 = 479, age: 14 years). We found that experimentally assessed positive memory specificity was associated with lower morning cortisol and less negative self-cognitions 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. Positive memory specificity actively dampened the negative effect of stressors over time, thereby operating as a resilience factor reducing the risk of subsequent psychopathology. These findings may have important clinical implications for at-risk populations. Our findings suggest that developing methods to improve positive memory specificity in at-risk adolescents may counteract vulnerability to depression.
