We conducted repeated measures ANOVAs to examine medication effects on EEG power. In BP, no significant effects of Medication were detected at any frequency. In SZ, there was a significant effect of Medication (F(1,129)=6.25, p=.014) at Alpha2, with unmedicated patients exhibiting greater power than medicated patients. There was also a significant Region by Medication interaction (F(3,387)=3.46, p=.024), driven by parietal (p=.002) and temporal regions (p=.014) only, whereby unmedicated patients showed greater power than patients on medication. At Beta1, there was a significant Region × Medication interaction (F(3,387)=3.15, p=.034) that was driven by the parietal region only (p=.009), with unmedicated patients displaying greater power. To account for these effects on our EEG variables, we included age, gender, and medication status as covariates in all subsequent analyses.
