Association between a father-unfriendly workplace culture, paternity leave, mental health and child abuse

• Paternity leave uptake in Japan remains low due to unsupportive work environments. • 36% took leave; 14% experienced difficulty related to workplace culture. • Leave difficulty linked to depression (OR = 2.05), distress (2.18), and neglect (2.96). • Workplace hostility, not leave, was tied to worse mental health and child neglect. • Supportive workplaces and better mental health care for fathers are urgently needed. Despite policy interventions, paternity leave uptake in Japan remains low due to unsupportive workplace cultures, posing risks to fathers’ mental health and child welfare. We conducted a cross-sectional study using data from the 2021 Japan COVID-19 and Society Internet Survey (JACSIS), including 929 fathers of children younger than 2 years. Fathers were categorised into four groups based on paternity leave uptake and workplace culture perceptions. Mental health outcomes were assessed using the Edinburgh Postnatal Depression Scale (EPDS) and Kessler 6 Scale (K6), while child abuse behaviours were evaluated through a validated indirect questionnaire. Logistic regression analyses were performed, adjusting for demographic, family, and COVID-19-related factors. Robustness checks were conducted following Oster’s (2019) method to account for potential bias from unobserved variables. Among respondents, 36 % took paternity leave (22.2 % without difficulty, 13.8 % with difficulty); 64 % did not. Fathers who faced difficulty taking leave had higher odds of depression (OR = 2.05, 95 % CI: 1.18–3.56), psychological distress (OR = 2.18, 95 % CI: 1.14–4.20), and child neglect (OR = 2.96, 95 % CI: 1.17–7.53) compared to those who took leave without difficulty. Robustness checks confirmed that these associations were unlikely to be biased by omitted variables. Taking paternity leave in a father-unfriendly workplace was associated with poorer mental health and increased child neglect among Japanese fathers. These findings highlight the need to foster father-friendly workplace cultures, implement psychological health screenings for fathers, and strengthen support systems to prevent child neglect and promote fathers’ well-being.