One of the main traits of a society of reflexive modernity is the critical analysis of categories that in the past appeared unquestionable. Socio-cultural gender and health or illness/mental disorders are categories of this type. Above all, they are socially constructed, that is, they are dependent on culture and on political, economic, and religious factors. The author undertakes to analyse the relations between the diagnostic criteria used in the international system of classifying mental diseases (DSM-IV and ICD-10) and traditional schemas of masculinity and femininity. Confirmation of the incidence of particular diseases in connection with gender is the author’s entry point for seeking answers to why individuals suffering from certain illnesses/mental disorders display behaviour corresponding to traditional gender roles, even though contemporary gender roles are fluid in many respects, and hypotheses about biological differences as causes of incidence of disease in men and women have not been empirically confirmed.