These results may be because of the normalization of dopamine function by clozapine and antagonism of 5HT2 receptors.
Drug-mediated symptom improvement, the traditional measure of treatment success for schizophrenia, typically fails to associate with modifications of cognitive dysfunction, resulting in a failure of the patient to reintegrate into society.
These studies provide (1) strong evidence
that clozapine Improves attention and-verbal-fluency
and (2) moderate evidence that clozapine improves
some types of executive function. However, results of
the effects of clozapine on working memory and secondary
verbal and spatial memory were inconclusive.
Risperidone has relatively consistent positive effects on
working memory, executive functioning, and attention,
whereas improvement in verbal learning and memory
was inconsistent Preliminary evidence presented here
suggests that olanzapine improves verbal learning and
memory, verbal fluency, and executive function, but
not attention, working memory, or visual learning and
memory