Daytime sleepiness and EEG abnormalities in patients treated with second generation antipsychotic agents

The aim of this study was to verify whether or not an increased prevalence of excessive daytime sleepiness (EDS) or EEG abnormalities is observed in patients with schizophrenia spectrum disorders (SSD), and to compare the effects of second generation antipsychotics (SGA) on patients' daytime sleepiness level and EEG recordings.

EEG recordings and self-reports of EDS, assessed with Epworth (ESS) and Stanford (SSS) Sleepiness Scales, were compared between 244 patients with SSD and 82 patients with anxiety, personality or behavioral disorders (non-psychotic disorders, NPD). To examine the effects of various SGA, patients treated in monotherapy with aripiprazole, olanzapine, clozapine, risperidone and sertindole were compared.

A higher prevalence of abnormal EEG recordings was observed in SSD patients. No significant differences in average daytime sleepiness were found between patients with SSD and NPD; however, patients with SSD had longer sleep duration. Aripiprazole treatment was associated with significantly smaller and less frequent EEG abnormalities than treatment with any other SGA, while treatment with clozapine and olanzapine was related to an increased prevalence of severe EEG abnormalities. Patients with SSD treated with SGA in monotherapy were less sleepy than unmedicated patients with NPD.

Although antipsychotics may have profound effects on EEG patients with schizophrenia do not have higher daytime sleepiness than patients with anxiety/personality disorders. Patients with schizophrenia may compensate sedative effects of antipsychotic treatment with sleep duration prolongation and report even less sleepiness than non-psychotic patients.