Sex difference in age of onset of schizophrenia: findings from a community-based study in India.

This study examined the sex difference in age of onset of schizophrenia in a community sample. Community-level health workers identified patients with symptoms of schizophrenia living in the community in a defined geographical area in South India. Two hundred and nine of them were diagnosed as hav-ing schizophrenia according to ICD-10 criteria by a team of psychiatrists. The age of onset of schizophrenia was assessed using the Interview for Retro-spective Assessment of Onset of Schizophrenia (IRAOS). The mean age of onset of schizophrenia did not significantly differ between males (29.2+/-8.8 years) and females (30.8+/-11.4 years) (t = 1.12; p = 0.27). Among those with an age of onset </=33 years, females had a significantly earlier onset; among those with an age of onset >33 years, females had a significantly later onset. The results from this community-based study confirm the previous findings in hospital-based patients in Asia. There is a need to revise the description of schizophrenia in the classificatory systems, keeping in view the regional varia-tions in the age of onset of the disorder.