background Genes for depression may act by making individuals more sensitive to childhood trauma.
aim Given that childhood adversity is a risk factor for adult psychosis and symptoms of depression and psychosis tend to cluster within individuals and families, the aim was to examine whether the association between childhood adversity and psychosis is moderated by genetic liability for depression. Second, it was examined to what degree a depression-related increase in stress-sensitivity or depressive symptoms themselves occasioned the moderating effect.
methods Female twin pairs (n = 260 pairs) completed both prospective and retrospective questionnaires regarding childhood adversity, Symptom Check List-90-R, scid interview (psychotic symptoms) and psychotic trait liability (Community Assessment of Psychic Experiences,cape). Furthermore, stress sensitivity was indexed by appraisals of event-related stress and negative affect (na) in the flow of daily life, assessed with momentary assessment technology for five consecutive days. Multilevel regression analyses were used to examine moderation of childhood adversity by genetic liability for depression in the prediction of follow-up psychotic experiences.
results The effect of childhood adversity was significantly moderated by genetic vulnerability for depression, in the model of both follow-up psychotic experiences (scl 90-R) and follow-up psychotic trait liability (cape). The moderation by genetic liability was mediated by depressive experience, but not by stress-sensitivity.
conclusion Genetic liability for depression may potentiate the pathway from childhood adversity to psychosis through dysfunctional emotional processing of anomalous experiences associated with childhood trauma.