How sex differences in schooling and income contribute to sex differences in depression, anxiety and common mental disorders: The mental health sex-gap in a birth cohort from Brazil.
BACKGROUND
Reasons for the higher rates of depression, anxiety and common mental disorders among women are unclear. We investigated the mediating effect of schooling and personal income and the effect modification of maternal schooling and family income at baseline.


METHODS
In 1982, the maternity hospitals of Pelotas (Southern Brazil) were daily visits and those livebirths whose family lived in the urban area of the city were examined and their mothers interviewed. At 30 years, the presence of major depression (MD) and generalized anxiety disorder (GAD) was assessed using the Mini-International Psychiatric Interview, and common mental disorders (CMD) with the self-rated questionnaire. We used Mantel-Haenszel test to assess effect modification and a counterfactual framework using inverse probability weights (IPW) and G-computation to analyze mediation.


RESULTS
Income at 30 years captured part of the association of sex with MD (16.5%), GAD (14.2%), and CMD (18.0%). Schooling at 30 years was higher in women (p<0.001), and therefore inversely mediated the association with MD (-5.4%), GAD (-4.8%), and CMD (-6.7%). If we fixed the mediator to earning more than 3 minimum salaries, the effect of sex, was reduced in 64.9%, 56.7% and 31.4%, for MD, GAD and CMD, respectively, and 62.4%, 13.6% and 23.8%, if fixed to 12 or more years of schooling.


LIMITATIONS
We were not able to evaluate mental health and socioeconomic changes, or assess a bidirectional effect CONCLUSION: Personal income and schooling at 30 years, are important mediators and effect modifiers of the association between sex and MD, GAD, and CMD.
['Loret de Mola|Christian|C|', 'Carpena|Marina Xavier|MX|', 'Gonçalves|Helen|H|', 'Quevedo|Luciana de Avila|LA|', 'Pinheiro|Ricardo|R|', 'Dos Santos Motta|Janaína Vieira|JV|', 'Horta|Bernardo|B|']
D001007:Anxiety D001008:Anxiety Disorders D001938:Brazil D003863:Depression D005260:Female D006801:Humans D008297:Male D001523:Mental Disorders D008603:Mental Health D011247:Pregnancy D015995:Prevalence D012727:Sex Characteristics
Sex Depression Anxiety Women Socioeconomic position