The development of peripartum depressive symptoms is associated with gene polymorphisms of MAOA, 5-HTT and COMT

We found that MAOA in combination with COMT appears to regulate not only the stress response in laboratory experiments, but also seems to influence the stress-evoked onset of mood during normal, mild, stressful events, such as experienced in the peripartum period. These findings support the G × E concept for depression, but they underline the complexity of this concept, as the cumulating effects of these polymorphic genes (i.e. MAOA + COMT) might be needed and the effects of these polymorphic genes becomes apparent in special environmental or physiological conditions (i.e. the peripartum period). We therefore suggest that G × E interactions become especially noticeable from longitudinal study designs in specific physiological or social challenging periods.