A majority of the studies on cognition in schizophrenia have been conducted in drug-treated patients. In healthy subjects, administration of antipsychotic medication has been found to have a negative impact on cognitive performance in domains such as speed of processing and attention. Antipsychotic drugs occupy the D2-dopamine receptor, a receptor subtype that has been related to cognitive function. Studies employing Positron Emission Tomography have shown that poor performance in several cognitive domains is associated to low D2-receptor binding. It is therefore crucial to examine cognition in drug-naïve patients with schizophrenia.

In FES patients: To examine the profile of cognitive impairments in the absence of antipsychotic medication and compare with the cognitive profile of patients who are on antipsychotic medication.

To study cognition in FES.

The Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) battery was administered to 60 patients with early schizophrenia and 30 healthy controls, 50% of the patients were drug-naïve. This research is ongoing and a part of the Karolinska Schizophrenia Project (KaSP), a multidisciplinary research consortium that examines the pathophysiology of schizophrenia.

Preliminary findings show that patients perform worse than healthy controls in all cognitive domains, with no significant differences between drug-naïve and medicated patients. Attention and Visual memory were the domains with the greatest impairments. The results are compared with our previous meta-analytic findings in drug-naïve patients.

These preliminary findings confirm the existence of cognitive impairments at the early stage of schizophrenia in the absence of antipsychotic medication.