Objective: Clozapine is seen as a gold standard for treatment refractory schizophrenia; however, it is not recommended for the treatment of first-episode psychosis mainly due to concerns of severe side effects. An indicator for response holds tremendous clinical value to select patients who can benefit from clozapine, safely. EEG abnormality has been reported to be one such parameter, yet the definite conclusion of the nature of EEG changes and its predictive value remains undetermined. The present study was undertaken to examine electroencephalographic (EEG) abnormalities and clinical response subsequent to clozapine therapy in schizophrenia. Methods: A total of 80 first-episode patients were recruited for a 12 week study, from a tertiary care centre in Mumbai, India. First episode was defined as an illness of less than 2 years duration and first hospitalization since illness. EEG abnormalities, psychopathology, and positive and negative symptoms were examined at baseline and again after 12 weeks of clozapine treatment. Results: There were some types of EEG abnormalities found in pretreatment state in at least two-thirds of patients. The number of patients showing EEG abnormality at the end of the 12 weeks of treatment increased significantly, which included theta (θ) frequency, slow waves, and sharp waves. Symptomatically, significant improvement was seen in both positive as well as negative symptoms scores. However, there was no significant correlation between EEG changes and clinical outcome. Conclusion: There was significant abnormality in the number of patients exhibiting EEG abnormalities. Baseline pretreatment EEG abnormalities were present in a considerable number of patients, and these EEG abnormalities did not significantly correlate with clinical improvement, except suggesting a trend towards such correlation.
Electroencephalography