Can Breast-Feeding Protect against Schizophrenia?. Case-Control Study

The aim of this study was to compare the incidence and length of breast-feeding in patients, siblings and normal controls and to examine the relationship between the duration of breast-feeding and age at onset of schizophrenia. 113 schizophrenic patients were recruited, as were 140 siblings of the patients and 113 nonschizophrenic controls. The breast-feeding history of the patients, their siblings and controls was obtained through interviews with the mothers of the patients and controls. There were no significant differences between groups in the incidence of breast- feeding. The duration of breast-feeding was positively correlated with the age at onset of illness (r = +0.25, p < 0.02). Breast-feeding is no less common in those who develop schizophrenia in later life. However, breast milk might postpone the onset of the illness in schizophrenic patients.