Variations in the seasonal distribution of births of psychotic patients in England and Wales.

The quarterly distribution of births of patients born in England and Wales 1921-60 and first admitted in 1970-75 was examined by decade of birth and by age at year of admission. For patients with schizophrenia and affective psychosis, the distribution varied: in the early decade (1921-30), and for older patients (45-54 years) the proportion of births in the fourth quarter of the year was high, compared with expectation from live births in the general population; but it became lower in succeeding decades and for younger age groups. No comparable change occurred for births of patients with neurosis or personality disorder.