To the Editor.
—It was with great interest that we read the excellent report by Sherwin et al, "Prevalence of Psychosis in Epilepsy as a Function of the Laterality of the Epileptogenic Lesion" (Archives 1982;39:621-625), showing a relationship between schizophreniclike psychosis and a temporal lobe epileptiform focus lateralized to the left hemisphere. In this important area, Sherwin confirmed his own earlier findings,1 as well as those of others.2,3 The purpose of this letter is to offer some methodologic observations concerning the discussion of Sherwin et al regarding the prevalence of psychosis in persons with temporal lobe epilepsy (TLE).In epileptology, specifically in regard to adults with epilepsy, we unfortunately have no population-based studies regarding the prevalence of psychosis in persons with epilepsy in general (and TLE in particular) relative to other chronicillness and neurologic control groups. Such data are needed so that the increased risk of psychosis