In general, parents and people in stable relationships have better mental health than the childless and single. In the last decades, however, more people than before are single or childless. These societal changes could have consequences for the mental health of the population, but it is largely unknown what these consequences are, if any. Our aim is therefore to understand how mental health is linked with reproductive behaviour.
The project has three sub-aims, corresponding to our work packages. First, mental health could influence whether one finds a partner and wants to have and affords to have children. We therefore investigate how mental health relates to later family formation. Second, parenthood could influence mental health, in both good and bad ways. Previous studies on this have several limitations. We use new research methods to circumvent these limitations. We also look at effects of becoming a grandparent. Third, couples are not randomly composed. Partners often have similar levels of education and mental health. We investigate how this may enhance social health differences.
We address these methods with longitudinal register data on the Norwegian population. In addition, we plan to use data from approximately 230 000 individuals in The Nord-Trøndelag Health Study. We combine research methods from epidemiology, genetics, and econometrics. When this project is finished, we will have a better understanding of why some people have children whereas other do not. We will also know how that might influence their mental health. Of particular importance, we provide knowledge on the mental health among the childless, a group that often receives little attention.
Finding a partner and having children are life-changing events and positively correlated with mental health. In the last decades, the proportion of childless individuals has increased. The potential consequences of these changes for the mental health of the population are unknown. Our aim is to understand how mental health is linked with reproductive behaviour of men and women.
First, mental health may influence the probability of having a partner, the desire to have children, and economic conditions. Mental health as a determinant of fertility is understudied. We investigate how mental diagnoses and broad vulnerabilities influences marriage and parenthood, and how this may have changed over time. Second, reproduction could influence mental health, but studies on the effects of parenthood have short follow-up time or are not causally informative. We therefore triangulating several methods for causal inference and to determine how effects of parenthood and grandparenthood may vary by individual characteristics. Third, having children is a couple level phenomenon, but most intergenerational studies do not account for the fact that partners are often similar. The composition of couples can have consequences for the children through the amount of risk and protective factors they experience. Such effects are largely unexplored. We will therefore assess the consequences of assortative mating on mental health.
We use register data on the entire population of Norway that includes longitudinal information on kinship, mental health, education, and economic activity. In addition, we use survey and genomic data from ~230 000 individuals in The Nord-Trøndelag Health Study. We apply a toolbox of epidemiological, genetic, and econometric methods. This project will lead to an increased understanding of selection into parenthood and the causes of mental disorders. Of particular importance, we provide knowledge on the mental health of non-parents, a group that is often overlooked.