Persistent sedation is a side effect of antipsychotic drugs, with a substantial impact on quality of live and treatment adherence. Additionally sedation can contribute to weight gain and metabolic disturbances. It impairs also patient's driving skills. In present study we evaluated sedative effects of antipsychotic drugs using three methods that are accessible, and easy to use in psychiatric practice.

59 patients with schizophrenia (mean age 25.1 ± 3.6, 27 M, 22 F) were included to the study before the discharge from an open psychiatric ward. All patients underwent monotherapy with sedative (olanzapine; n=33, mean dose 15.4 ± 5.9), moderate -sedative (risperidone; n=12, mean dose 4.4 ± 1.8) and non-sedative (aripiprazole, sertindole; n=14, mean dose 18.7 ± 6.2, 15.5 ± 3.3) antipsychotics. The patients underwent EEG recordings, 28-minutes long psychomotor vigilance task (Mackworth Clock Test) and filled out Epworth Sleepiness Scale (ESS) and scales for assessment of sleep quality.

Increased slow-wave EEG activity was found in 21 (63.6%) of patients treated with olanzapine, 8 (66.7%) of patients treated with risperidone and 3 (21.4%) of patients treated with non-sedative antipsychotics (p< 0.05). Abnormal results of psychomotor task were found respectively in 10 (30.3%), 5 (41.7%) and 4 (28.6%) of patients (not significant). Mean ESS score was: 6.9 ± 3.3, 8.0 ± 3.0, 5.4 ± 3.7, respectively (not significant).

Signs of sedation were frequent in EEG recordings of patients treated with sedative antipsychotics, however at performance level in psychomotor task the differences between the investigated drugs were less pronounced.