The Nithsdale Schizophrenia Surveys 16. Breast-feeding and schizophrenia: Preliminary results and hypotheses

BACKGROUND: Schizophrenia may in some cases be a neurodevelopmental disorder. Breast milk is important to the developing brain. Might a lack of breast milk be an environmental risk factor in schizophrenia? METHOD: Mothers of 45 schizophrenic patients in Nithsdale, southwest Scotland, completed a questionnaire about whether or not their offspring had been breast-fed. RESULTS: The incidence of breast-feeding in patients was 29% and in sibs 38%. Most patients were born in the 1940s and 1950s. The incidence in patients born in these two decades, 33 and 26%, respectively, was significantly lower than in Scottish surveys in 1946 (81%) and 1958 (51%). Those patients who had not been breast-fed had more schizoid and schizotypal personality traits in childhood and a poorer social adjustment than their sibs; breast-fed patients did not differ from their sibs. CONCLUSIONS: Fewer schizophrenic patients than normal were breast-fed. Lack of breast milk may be a risk factor in the neurodevelopmental form of schizophrenia.