Is there a sex-specific difference in onset age of schizophrenia that started before age 18?

Schizophrenia in male adults starts on average 4-5 years earlier than in females. The lifetime risk for both sexes is equal. It is still unknown, whether this observation is also valid for children and adolescents. This question was examined in the present study by means of data from the literature and a study of our own (n=118). From a total of 28 studies, only eight used standardized diagnostic criteria and confined the age range from 11 to 18 years. Neither the data of these eight studies nor those of the Mannheim-Study indicate an earlier onset of schizophrenia in male adolescents. Possible reasons are discussed.