Number of children and the prevalence of later-life major depression and insomnia in women and men: findings from a cross-sectional study of 0.5 million Chinese adults

BACKGROUND: Pregnancy and parenthood have been associated with physical and mental health. Previous literature concerning the impacts of parity on mental health was inconsistent and lack epidemiolocal evidence. China, with growing mental health problems and changing fertility patterns, faces unique challenges. This study aims to examine the relationship between parity and the prevalence of major depression and insomnia among men and women in the Chinese population. METHODS: Baseline data from a Chinese population-based study of 512,891 adults (59.01% women) from 10 areas, aged 30–79 were analyzed. Number of children was based on self-report by the participants. Major depression (MD) was assessed using the Composite International Diagnostic Inventory. Insomnia symptoms were accessed by a questionnaire comparable to that used in the Diagnostic and Statistical Manual of Mental Disorders. Logistic regression was used to assess the relationship between MD/Insomnia and number of children, after stratifications and adjustments. RESULTS: For women, each additional child was associated with a 9% decreased odds of MD (OR: 0.91, 95%CI: 0.88–0.96), with the associations significant for those who lived in urban areas (OR: 0.76, 95%CI: 0.70–0.83), or had a lower education (OR: 0.90, 95%CI: 0.85–0.94), or had lower household income (OR: 0.89, 95%CI: 0.85–0.94), or had ever used alcohol (OR: 0.89, 95%CI: 0.84–0.93). The association between per additional children and MD was not significant in men (OR: 1.02, 95%CI: 0.97–1.07), but a decreased odd of MD with per additional child was found in men who lived in urban areas (OR: 0.81, 95%CI: 0.71–0.96). For women, each additional child was associated with a 4% decreased odds of insomnia (OR: 0.96, 95%CI: 0.95–0.96). Each additional child was also associated with a 2% decreased odds of insomnia in men (OR: 0.98, 95%CI: 0.97–1.00). CONCLUSIONS: MD and insomnia were inversely associated with number of children in women while the association was not overall significant in men. The association was mediated by socioeconomic and lifestyle factors. Future mental health public health programs should address parity and sex differences when designing interventions.