A Biopsychosocial and Long Term Perspective on Child Behavioral Problems Impact of Risk and Resilience

Abstract: Mental health has become a prominent issue in society. Yet, much remains unknown about the etiology of psychiatric disorders. The aim of the present thesis was to investigate the association between biological, psychological and social factors of risk and resilience and behavioral problems in a birth cohort of Swedish children. 1723 mothers and their children were followed from birth to the age of 12 as part of the South East Sweden Birth Cohort Study (the SESBiC study). Information was gathered through register data, standardized questionnaires and DNA samples.In study I, stability of maternal symptoms of depression and the impact on child behavior at age 12 were investigated. The prevalence of depressive symptoms was found to be 12.0 % postpartum. Symptoms of postpartum depression significantly increased the risk for subsequent depressive symptoms 12 years later in women. Children whose mothers reported concurrent symptoms of depression and anxiety had an increased risk for both internalizing and externalizing problems at age 12, but no long term effect on child behavior was seen for postpartum depressive symptoms. The greatest risk was seen for children whose mothers reported symptoms of depression on both occasions. In study II, the impact of gene-environment interaction of 5-HTTLPR and BDNF Val66Met and experience of life events together with symptoms of maternal depression and anxiety on child behavior at age 12 was studied. A main effect of 5-HTTLPR was noticed, but no geneenvironment effects were shown. Similarly to study I, concurrent symptoms of maternal depression and anxiety were an important predictor of child behavioral problems. A high degree of psychosocial stress around childbirth was found to have long lasting detrimental effects on child behavior, increasing the risk for internalizing problems at age 12. Study III investigated the impact of geneenvironment interactions of 5-HTTLPR and BDNF Val66Met and life events together with symptoms of maternal depression and birth characteristics on behavioral problems at age 3. Symptoms of postpartum depression were found to predict internalizing as well as externalizing problems in children three years later. Child experience of life events was a stable predictor of behavioral problems across the scales similar to sociodemographic factors such as parental immigration status and unemployment. No gene-environment interaction effects of 5-HTTLPR or BDNF Val66Met were shown. Study IV used the risk factors identified in studies I-III to investigate factors of resilience to behavioral problems at age 12. The l/l genotype of 5-HTTLPR was associated with a lower risk for behavioral problems at age 12, especially for children facing low adversity. Good social functioning was found to be a general resource factor, independent of the level of risk, while an easy temperament was associated with resilience for children with a high degree of adversity. However, effect sizes were small.In summary, the results from the present thesis emphasize the importance of maternal mental health and sociodemographic factors for child mental health at ages 3 and 12, which must be taken into account in clinical settings. Moreover, it adds to the null-findings of the gene-environment effect of 5-HTTLPR and BDNF Val66Met on behavioral problems in children, but indicates a main effect of 5-HTTLPR on internalizing symptoms at age 12.