Effect of gene, environment and maternal depressive symptoms on pre-adolescence behavior problems - a longitudinal...

Depression is a common and disabling condition with a high relapse frequency. Maternal mental health problems and experience of traumatic life events are known to increase the risk of behavior problems in children. Recently, genetic factors, in particular gene-by-environment interaction models, have been implicated to explain depressive etiology. However, results are inconclusive.

Study participants were members of the SESBiC-study. A total of 889 mothers and their children were followed during the child's age of 3 months to 12 years. Information on maternal depressive symptoms was gathered postpartum and at a 12 year follow-up. Mothers reported on child behavior and traumatic life events experienced by the child at age 12. Saliva samples were obtained from children for analysis of 5-HTTLPR and BDNF Val66Met polymorphisms.

Multivariate analysis showed a significant association between maternal symptoms of depression and anxiety, and internalizing problems in 12-year-old children (OR 5.72, 95% CI 3.30-9.91). Furthermore, carriers of two short alleles (s/s) of the 5-HTTLPR showed a more than 4-fold increased risk of internalizing problems at age 12 compared to l/l carriers (OR 4.73, 95% CI 2.14-10.48). No gene-by-environment interaction was found and neither depressive symptoms postpartum or traumatic experiences during childhood stayed significant in the final model.

Concurrent maternal symptoms of depression and anxiety are significant risk factors for behavior problems in children, which need to be taken into account in clinical practice. Furthermore, we found a main effect of 5-HTTLPR on internalizing symptoms in 12-year-old children, a finding that needs to be confirmed in future studies.