Fathers in Sweden were less likely to receive new psychiatric diagnoses during their partner’s pregnancy and in the first months after birth, but diagnoses of depression and stress-related disorders rose by more than 30% toward the end of the child’s first year, according to a large national register study published in JAMA Network Open.
Researchers from Karolinska Institutet in Sweden and Sichuan University in China analyzed linked national register data covering 1,096,198 fathers of children born in Sweden between January 1, 2003, and December 31, 2021, tracking new psychiatric diagnoses from one year before conception through one year after pregnancy.
Across the cohort, the incidence of diagnosed psychiatric disorders declined during pregnancy and early postpartum compared with the year before conception, then returned toward preconception levels later in the first postpartum year. Diagnoses related to anxiety and substance use disorders followed a similar pattern, returning to approximately baseline levels by about one year after birth.
By contrast, the study found that depression and stress-related disorders increased toward the end of the first postpartum year, rising by more than 30% relative to preconception rates.
“The transition to fatherhood often involves both positive experiences and a range of new stresses,” said Jing Zhou, a PhD student at Karolinska Institutet’s Institute of Environmental Medicine and a co–first author of the paper. She noted that while many fathers value time with their child, relationship strain and disrupted sleep can add stress that may contribute to mental health problems.
The pattern was not what the team expected, said Donghao Lu, a senior lecturer and associate professor at the Institute of Environmental Medicine at Karolinska Institutet and the paper’s corresponding author. “The delayed increase in depression was unexpected and underscores the need to pay attention to warning signs of mental ill-health in fathers long after the birth of their child,” he said.
The researchers cautioned that the findings are based on clinical diagnoses, meaning they capture only men who sought care and were diagnosed within the registers used. Still, they argued that identifying periods of heightened vulnerability could help healthcare providers and other stakeholders time support to fathers who may be at risk.
The study included collaboration with Uppsala University in Sweden. The authors reported no conflicts of interest and said the work was funded by Karolinska Institutet’s Strategic Research Area in Epidemiology and Biostatistics, the Swedish Research Council, and the European Research Council.
