Reproductive rates in families of schizophrenic patients in a case-control study.

Data about the fertility of 142 schizophrenic patients and their ancestors are reported and compared with healthy people in a case-control study. The biological fitness of the patients is 76% of controls in individuals with at least one child, and 48% of controls in all patients, with clear low fertility rates in patients, especially in men. When looking at the previous generations, the existence of a significant increase in fertility in the relatives of schizophrenics was reinforced in the maternal lineage. These results confirm the previous findings about the decreasing fertility in schizophrenic patients and may be of interest in understanding the maintenance of the illness despite its genetic background.