An Exploration and Cross Cultural Comparison of Mental Health Outcomes Associated with Single Parenthood

Single parenthood is a risk factor for mental health deficits, an effect that may be exacerbated by circumstances such as socioeconomic status (SES) or number of children in the household. To date, however, there are no genetically informed studies examining the association between single parenthood and mental health, which may have non-causal, family-level confounds. The present study used male and female pairs of MZ and DZ twins from United States (the Washington State Twin Registry) and Swedish (the Study of Twin Adults: Genes and Environment) datasets to examine the causality of the relation between single parenthood and several mental health outcomes. We controlled for genetic and shared environmental confounds as we reexamined whether this association is consistent with a causal explanation. We then investigated whether this effect is modified by age, education level, income level, and number of children. We found a quasi-causal effect of single parenthood on depression and anxiety, such that in all analyses single mothers experienced higher levels of depression and anxiety than their partnered counterparts. This effect was mediated by SES in the US, whereas in Sweden it was present even after controlling for SES confounds. Single mothers were worse off than single fathers in all analyses. No effects of single parenthood on perceived stress or coping were found in our samples. Our results suggest a nuanced picture of the effect of single parenthood on mental health outcomes. Sociopolitical climates and economic differences do not fully account for mental health disparities between single and partnered mothers across cultures.