Investigating environmental links between parent depression and child depressive/anxiety symptoms using an assisted conception design

Objective: Links between maternal and offspring depression symptoms could arise from inherited factors, direct environmental exposure, or shared adversity. A novel genetically sensitive design was used to test the extent of environmental links between maternal depression symptoms and child depression/anxiety symptoms, accounting for inherited effects, shared adversity, and child age and gender. Method: Eight hundred fifty-two families with a child born by assisted conception provided questionnaire data. Mothers and fathers were genetically related or unrelated to the child depending on conception method. Parental depression symptoms were assessed using the Hospital Anxiety and Depression Scale. Child depression/anxiety symptoms were assessed using the Short Mood and Feelings questionnaire and six items tapping generalized anxiety disorder symptoms. Associations between maternal and child symptoms were examined separately for genetically unrelated and related motherchild pairs, adjusting for three measurements of shared adversity: negative life events, family income, and socioeconomic status. Analyses were then run separately for boys and girls and for children and adolescents, and the role of paternal depression symptoms was also examined. Results: Significant associations between parent and child symptoms were found for genetically unrelated motherchild (r = 0.32, p < .001) and fatherchild (r = 0.17, p < .05) pairs and genetically related motherchild (r = 0.31, p < .001) and fatherchild (r = 0.23, p < .001) pairs and were not explained by the shared adversity measurements. Environmental links were present for children and adolescents and were stronger for girls. Conclusions: The transmission of depression symptoms is due in part to environmental processes independent of inherited effects and is not accounted for by shared adversity measurements. Girls may be more sensitive to the negative effects of maternal depression symptoms than boys through environmental processes. © 2011 American Academy of Child and Adolescent Psychiatry.