Childhood adversity as a transdiagnostic risk factor for affective disorders in adulthood: A systematic review focusing on biopsychosocial moderating and mediating variables

This systematic review reports on moderating and mediating variables in the relationship between childhood adversity and affective disorders. Embase, MEDLINE & PsycINFO were searched from inception to October 2017, for English articles published in peer-reviewed journals investigating at least one moderating, mediating or otherwise associated variable in the relationship between childhood adversity and major depressive disorders, post-traumatic stress disorder, generalized anxiety disorder or social anxiety disorder. Overall, 214 studies were included. The review revealed that biological (i.e. heightened amygdala responses and structural neurological changes), psychological (i.e. emotional dysregulation, attachment anxiety, maladaptive cognitive style, emotion-focused coping, attentional biases, psychoform dissociation, maladaptive personality types, anxious arousal, lack of resilience, low self esteem and trauma-related guilt), and social (i.e. retraumatizations, chronic interpersonal stress, low social support and friendship) variables served as mediators between childhood adversity and affective disorders in adulthood. Furthermore, biological (i.e. genetic polymorphisms in the 5-HTT, BDNF, FKBP5, CRHR1, NR3C2, OXTR, ADCYAP1R1 genes, and alterations in the connectivity of the emotion processing circuitry), and psychological (i.e. romantic attachment avoidance and low self esteem) variables served as moderators in this relationship. A transdiagnostic moderation and mediation model is proposed, limitations are discussed and suggestions for future empirical studies are presented.