Mothers' symptoms of anxiety and depression and the development of child temperament: A genetically informative, longitudinal investigation.

BACKGROUND

Child temperament traits and mothers' emotional symptoms relating to anxiety and depression may drive changes in one another, leading to their 'co-development' across time. Alternatively, links between mother and child traits may be attributable to shared genetic propensities. We explored longitudinal associations between mothers' emotional symptoms and child temperament traits and adjusted for genetic effects shared across generations.

METHODS

This study is based on the Norwegian Mother, Father and Child Cohort Study (MoBa). Mothers ( = 34,060) reported on their symptoms of anxiety and depression, and temperament among offspring ( = 42,526), at child ages 1.5, 3 and 5 years. Structural equation models parameterised developmental change in traits, and an extended family design adjusted for genetic effects.

RESULTS

We found individual differences in stable trait scores and rate of change for all study variables. Longitudinal in mothers' emotional symptoms was associated with longitudinal in offspring emotionality ( = 0.143), shyness ( = 0.031), and sociability ( = -0.015). Longitudinal in mothers' symptoms showed very small or negligible correlations with longitudinal in child temperament. Both genetic and environmental influences explained the stable longitudinal association between mothers' symptoms and child emotionality.

CONCLUSIONS

The studied associations between mother and child traits across time appeared to be due to stable, trait-like factors, involving genetic and environmental influence, rather than their co-development. Findings contribute knowledge on how emotional symptoms develop in families across time, and the methods with which we can explore such development.