This study is a retrospective reportof childhood neurobehavioral assessment in adult patients with schizophrenia and healthy controls using the CBCL (Child Behavior Checklist) to elucidate the subclinical characteristics of schizophrenic children and to find out indicators which predict later development of schizophrenia.

Schizophrenia outpatients in his/her twenties who fulfill DSM-IV-TR criteria and who present now mainly negative symptoms after passing an acute stage were investigated. Normal healthy subjects were also examined as sex- and age-matched controls. By modified use of the CBCL as a retrospective assessment questionnaire, the parents of the patients and of control subjects rated their childhood (aged 6-8years) behaviors.

Among the eight CBCL syndromesubscale T-scores, those of Withdrawn, Anxious/Depressed, and Social problemswere significantly associated with schizophrenia, although any of these scores were not in clinical range. Patients also showed a significantly attenuated aggression. With cross validation, a discriminant analysis using the eight syndrome subscales adequately classified 82% of the population.

The results suggest that subclinical neurobehavioral characteristics of schizophrenia already exist in the patients' childhood. The combination of these characteristics would predict later development ofschizophrenia. Furthermore, quite early screening for the risk of schizophrenia could be possible with some instrument using obtained discriminant function.