Evaluation and interpretation of symptom structures in patients with schizophrenia

Seventy Japanese DSM-III-R schizophrenic patients were assessed for 30 clinical symptoms using the Positive and Negative Syndrome Scale (PANSS) of Kay et al. Principal component analysis was applied to the full item set of this scale and disclosed 5 orthogonal independent symptom groups: negative, hostile/excited, thought-disordered, delusional/hallucinatory and depressive components. Our results provided further support of the contention that more than 2 (i.e., positive and negative) dimensions are required to account for structures of the schizophrenic symptoms.