The clinical use of EEG in a general psychiatric setting.

In a university teaching hospital, the charts of 150 psychiatric inpatients consecutively referred for EEG were reviewed to survey the clinical use of the EEG by psychiatrists. Individual psychiatrists referred between 18 and 31 percent of their caseloads, and 11.3 percent of the EEGs were abnormal. The only clinical indications significantly associated with an abnormal EEG were a history of epilepsy and suspicion of a recent seizure. The presence of an organic factor, which was previously identified in the history, mental status examination, or physical examination of 58 percent of the patients, was significantly associated with an abnormal EEG. However, none of the abnormal EEGs helped identify an organic etiology that was not already diagnosed, and in three cases clinicians appeared to ignore abnormal EEG results. Based on these data, the authors discourage the routine use of the EEG for psychiatric patients, recommending that an EEG be considered only when the clinical history and findings suggest an underlying organic disorder.