Effects of clozapine on awareness of illness and cognition in schizophrenia.

Awareness of illness is a crucial factor in schizophrenia, both for clinical management and psychopathological modeling. To date, there has been relatively little investigation of the influence of treatment with conventional versus atypical neuroleptics in relation to awareness and cognitive functions. The effect of clozapine treatment, compared with conventional neuroleptics, was studied in 22 schizophrenic patients in a crossover study. The P300 component of the event-related potential and scores on the Scale for Unawareness of Mental Disorder (SUMD), the Extrapyramidal Side Effects Scale (EPS), and Andreasen's Scales for the Assessment of Positive (SAPS) and Negative Symptoms (SANS) were studied at time 1 (conventional neuroleptic treatment) and time 2 (after 6 months of treatment with clozapine, in patients who interrupted the previous conventional regimen). Significantly increased P300 amplitudes were associated with clozapine treatment, together with heightened insight and reduced involuntary movements. The results confirm the effectiveness of clozapine not only in enhancing neurocognitive function, but also in increasing awareness of illness in schizophrenic patients.