Relationship between neuroleptic dosage and subjective cognitive dysfunction in schizophrenic patients treated with either conventional or atypical neuroleptic medication.

Previous research has suggested that high doses of conventional neuroleptics may induce neurocognitive deficits when assessed with standard tasks. However, little is known about the effects of high doses of neuroleptics (conventional or atypical) on subjective cognitive dysfunction. Recent research stresses the putative importance of self-reported cognitive deficits for both symptomatic outcome and medication compliance. The aim of the present study was to investigate the impact of neuroleptic medication on subjective cognition in patients treated with either conventional or atypical agents (clozapine, risperidone, olanzapine). Patients were asked to endorse the items of a questionnaire entitled 'Subjective Well-Being under Neuroleptic Treatment' prior to discharge. Subjective impairment, as assessed with the subscale 'mental functioning', was significantly correlated with greater conventional neuroleptic dosage after controlling for psychopathology (P<0.05). The difference between patients medicated with higher doses of conventional neuroleptics and those with lower doses was highly significant (P<0.001). In contrast, higher atypical neuroleptic doses were not associated with impairment.