In addition to investigating all studies together, we also utilized a grouping method proposed in an earlier review to stratify studies by the type of stressor studied (Childhood Maltreatment, Specific Medical Conditions and Stressful Life Events) and assessed the presence of the association within each group9. When publications reported results for multiple types of stressors that matched different groups, we included the study in each relevant group1, 46, 58–61.
