Depression is a common psychiatric disorder that places a great burden on the public health system. Major depressive episodes (MDEs) often are preceded by life stress, characterized by recurrence, associated with dysfunction of biological systems acutely responsive to stress, and predicted by an interaction of stressful events and cognitive vulnerability. The probability of recurrence increases with the number of prior MDEs, suggesting the importance of examining both stable and dynamic markers of risk in individuals whose depressive episodes have remitted. The proposed study will investigate the relations among history of depression, hypothalamic-pituitary-adrenal (HPA) axis functioning, coping, and cognitive vulnerability in remitted and never depressed individuals by measuring stress reactivity to and recovery from a psychosocial laboratory stressor, the Trier Social Stress Test (TSST). The TSST to be used in the present study consists of a 5-minute free-speech task and a 5-minute unsolvable block puzzle task administered sequentially presumably before an audience of evaluators. This task is particularly appropriate for research on stress responses in participants at risk for depression because of its social evaluative nature. Participants will include 90 young adults (18-30 years old) recruited from three southern universities. Participants will be assessed regarding their current and past history of mood disorders with the SCID-I. Physiological arousal will be assessed with regard to Cortisol response and recovery to baseline, in anticipation of, and after the TSST. The following hypotheses will be examined: (a) individuals with remitted depression (RD) will show lower stress reactivity and slower stress recovery than never depressed (ND) individuals, (b) RD individuals will be less able to discriminate between high versus low level stressors compared to ND individuals, (c) RD individuals will report greater use of disengagement coping than ND individuals. Disengagement coping will correlate significantly and negatively with stress reactivity, (d) RD individuals will exhibit higher levels of implicit cognitive vulnerability following a stressor than will ND individuals;implicit cognitive vulnerability will be negatively correlated with stress reactivity. Public Health Significance: Results from this study will help further our understanding of the links between biological and cognitive markers associated with increasing risk of recurrence of depression over time. This knowledge can be used to inform the development of interventions for treating and preventing subsequent episodes of major depressive disorder, thereby reducing the cost of this debilitating condition to both the individual and society.
