The main purpose of this study was to investigate the relationship between short-term clinical outcome and changes in electroencephalogram ( EEG) power after drug treatment in patients with schizophrenia, and also to compare two different methods for quantitative EEG analysis. EEG power analysis was performed by both conventional fixed frequency band and adjusted frequency band based on individual alpha frequency (IAF) in 16 drug-naive patients before and after drug administration. In the theta bands determined by both conventional fixed band and IAF methods, the EEG power after treatment was larger than that before treatment. In addition, there was a correlation between EEG power and clinical drug response evaluated by changes in BPRS score. With regard to this correlation, IAF methods showed no apparent advantage over methods using conventional fixed frequency bands. Conventional quantitative EEG analysis can still serve as a useful tool for the assessment of short-term outcome of drug treatment. Copyright (C) 2005 S. Karger AG, Basel.