Forty-four first-admission patients with childhood-onset schizophrenia (age at onset < or = 14 years) were examined retrospectively for 30 clinical symptoms using the Positive and Negative Syndrome Scale (PANSS; 15). A principal component analysis with varimax rotation was applied to the full item set of this scale and revealed five orthogonal independent symptom groups: cognition affect, social withdrawal, anti-social behavior, excitement, and reality distortion. In order to validate these psychopathological dimensions we analyzed the relation between the five factor scores and outcome variables (Disability Assessment Schedule, DAS-M; 13) several years after onset: Social withdrawal was correlated with poor outcome; reality distortion was related to good outcome (P < 0.01). A multivariate ANOVA identified group differences in the anti-social behavior factor between acute and insidious onset of illness and between boys and girls; patients with an acute onset scored significantly higher on the excitement factor than those with an insidious onset (P < 0.05). According to our results more than two dimensions are necessary to describe the psychopathology of childhood-onset schizophrenia, similar to adolescent- and adult-onset schizophrenia.