Improvement of cognitive flexibility and cingulate blood flow correlates after atypical antipsychotic treatment in drug-naive patients with first-episode schizophrenia.

The aim of this study was to examine the changes in cognitive flexibility and associated cerebral blood flow in the anterior cingulate lobe of drug-naive patients with first-episode schizophrenia who were treated with atypical antipsychotics for 6 weeks. Single photon emission computed tomography (SPECT) images were obtained from 8 healthy subjects both at rest and while performing the flexibility subtest of the TAP (Test for Attentional Performance). SPECT images were obtained in parallel from 8 first-episode drug-naive schizophrenic patients while they were performing the same task both before and after 6 weeks of neuroleptic treatment. In the control group, an increase in the perfusion indices of the dorsal section of the anterior cingulate gyrus was observed in the activation condition. Task performance was altered and the level of perfusion of the brain region related to the task execution was significantly decreased in the patients at baseline. After treatment, there was a significant improvement in both task performance and the level of perfusion of the dorsal section of the anterior cingulate. We conclude that treatment with second-generation neuroleptics improves cognitive flexibility, and there was a relationship between such improvements and normalization of perfusion indices of the involved brain areas.