2. Stress: The studies vary widely on the types of assessments of stress and on the relative timing of the stressful event and the onset of depression. This study will examine two main stress assessments: a narrowly focused stressor, childhood maltreatment (most frequently used assessment among our participating groups: the Childhood Trauma Questionnaire (CTQ) [41]), and a broader defined stressor class, lifetime stressful events (most frequently used assessment: the List of Threatening Events (LTE) [42]). A second dimension we will investigate is timing of stress exposure relative to the assessment of depression. Some analyses will require that timing is known, while others will be broadened to include datasets where the timing is uncertain. A comprehensive list of the stress variables used in the analyses can be found in Additional file 2: Table S2.
