Early Chronic Stress and Development of Depression: Mechanisms of Risk -
DESCRIPTION (provided by applicant): Experience of a chronic stressful life event is one of the most supported risk factors for development of depression; however, little is known about the cognitive and physiological mechanisms linking early chronic stress and depression. Previous research has shown that chronically stressed adolescents show heightened attention to sad stimuli (i.e., biased attention) while in a sad mood that may intensify the mood experience, and heightened physiological reactivity to acute stressors. Work in field of depression suggests that depressed individuals also show heightened attention to sad stimuli, and frequently engage in perseverative attention to negative stimuli, or rumination. Additionally, these individuals show impaired physiological recovery from acute stressors. To date, integration among these multiple domains of research is lacking. It remains unclear how an individual progresses from mood-related biased attention and stress reactivity to the prolonged, intense mood experience of depression. Also unexplored is whether heightened or perseverative attention contribute to physiological arousal and subsequent physiological reactivity and recovery. The proposed research is a novel set of studies exploring the cognitive and physiological consequences of early chronic stress that may confer risk for depression, and testing the precise nature of the interaction between these domains. Specifically, the aims of the research are 1) to determine if chronically stressed adolescents show immediate and prolonged attention biases to sad stimuli in a sad mood, whether prolonged attention bias is related to rumination, and whether attention biases are related to heightened physiological arousal, 2) to test whether information processing anomalies causally influence physiological reactivity and recovery processes, and 3) whether chronically stressed adolescents who show immediate and prolonged attention biases are at heightened risk for depression prospectively. We will use an attention task with task- irrelevant emotional face stimuli and measure differential reaction times of chronically stressed and control adolescents for different emotional stimuli as a measure of biased attention. We will use blood pressure monitors and cortisol measurements to assess physiological reactivity and recovery.
PUBLIC HEALTH RELEVANCE: Depressive disorders are the leading cause of disability worldwide, and approximately 20% of the population will experience a depressive episode at some point in their life. Isolation of risk factors and mechanisms of risk lays the groundwork for development of effective early interventions that can be implemented before an individual develops depression, to effectively reduce the personal, economic, and social burden of the illness.
