Age-of-onset data were gathered on 93 chronic schizophrenic probands and 57 affected (mainly schizotypal) siblings. 55 of affected individuals were ill before age 20 and 14 had their onset before age 14. The risk period for schizophrenia and schizotypal personality disorders terminated at age 40. Age-of-onset did not distinguish paranoid from nonparanoid schizophrenics, or definite from probable schizotypal personalities. Schizophrenic and schizotypal subjects were similar in their age-of-onset patterns. Sex effect on age-of-onset was not present. A square-root normal distribution gave the best fit to the data. The implications of these findings for schizophrenia research were discussed.
展开▼
