The brain damage hypothesis of the seasonality of births in schizophrenia and major affective disorders: evidence from computerised tomography.

Although the excess of schizophrenic births in the winter and early spring has been replicated and some non-conclusive work supports the same seasonal birth trend in patients with major affective disorders, the aetiopathogenetic foundations of this phenomenon remain uncertain. The primary role of perinatal seasonal factors that predispose to the development of schizophrenia via induction of brain damage has been invoked, as has a tendency for patients to conceive during the spring and early summer. In order to test these two hypotheses, cerebral ventricular size and cortical atrophy in 206 schizophrenics and 107 patients with major affective disorders were assessed by CT and analysed in relation to month of birth.

Cortical atrophy in schizophrenia. Prevalence and associated features.

The degree of cortical atrophy as revealed by computed tomographic scans was assessed in 124 patients meeting the DSM III criteria for schizophrenia and in 45 age- and sex-matched healthy controls. 21 patients, i.e.