Symptoms of depression and internalizing problems in early adulthood - associated factors from birth to adolescence

PURPOSE

Even though the mechanisms behind the development of depression and internalizing problems remains unknown, many different factors have been shown to increase the risk. Longitudinal studies enable the investigation of exposure during different developmental periods during childhood. This study aims to examine factors associated with depressive and internalizing problems at age 20 in terms of sociodemographic factors, previous mental health problems and stressful life events during childhood, adolescence, and early adulthood.

METHODS

A birth cohort of 1723 children were followed to age 20. At the 20-year follow-up, n = 731 (44%) participated. Standardized instruments were filled out at baseline and the 3-,12- and 20-year follow-ups.

RESULTS

Depressive problems at age 20 were associated with female gender, experience of interpersonal life events reported at age 20, bullying victimization and reports on paternal mental health problems. Participants with depressive problems were also less likely to have experienced adolescence as happy and to report that their father had been a good father. Internalizing problems at age 20 were, in addition, associated with internalizing problems at age 12 and reports on maternal mental health problems. Internalizing problems were associated with a lower likelihood of experiencing adolescence as happy in the final model.

CONCLUSION

Recent events (i.e. interpersonal life events and bullying) seemed to be the most influential factors on the development of internalizing and depressive problems. Internalizing problems during childhood increased the risk for internalizing problems in early adulthood, emphasizing the importance of early intervention. Fewer factors were found to increase the risk for depressive problems compared to internalizing problems.

Early predictors of behavioural problems in pre-schoolers - a longitudinal study of constitutional and environmental main and interaction effects

Background

The early environment is important for child development and wellbeing. Gene-by-environment studies investigating the impact of the serotonin transporter gene-linked polymorphic region (5-HTTLPR) and the Brain Derived Neurotrophic Factor (BDNF) Val66Met polymorphisms by life events on mental health and behaviour problems have been inconclusive. Methodological differences regarding sample sizes, study population, definitions of adversities and measures of mental health problems obstacle their comparability. Furthermore, very few studies included children. The aim of this study was to examine the associations between a broad range of risk factors covering pregnancy and birth, genetic polymorphism, experience of multiple life events and psychosocial environment, and child behaviour at age 3, using a comparably large, representative, population-based sample.

Methods

A total of 1,106 children, and their mothers, were followed from pregnancy to age 3. Information on pregnancy and birth-related factors was retrieved from the Medical Birth Register. Questionnaires on depressive symptoms, child behaviour and child experiences of life events were filled in by the mothers. Child saliva samples were used for genotyping the 5-HTTLPR and BDNF Val66Met polymorphisms. Multiple logistic regression was used to investigate the association between psychological scales and genetic polymorphisms.

Results

Symptoms of postpartum depression increased the risk of both internalizing and externalizing problems. Experience of multiple life events was also a predictor of behavioural problems across the scales. No gene-by-environment or gene-by-gene-by-environment interactions were found. Children of immigrants had an increased risk of internalizing problems and parental unemployment was significantly associated with both internalizing and externalizing type of problems.

Conclusion

This study shows the importance of the psychosocial environment for psychosocial health in preschool children, and adds to the literature of null-findings of gene-by-environment effects of 5-HTTLPR and BDNF in children.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-016-0614-x) contains supplementary material, which is available to authorized users.