Distinguishing Between Content and Form of Speech-Reply

In Reply.—  Dr Berenbaum cites a difference between our study¹ and his.² We are not the first to find an aggregation of thought disorder in the relatives of psychotic patients.^3-6 We believe that at least three requirements should be met if one seeks to determine whether thought disorder is present in clinically normal members of families in which there is a psychotic patient. First, evaluating personnel must be well trained and experienced with the instrument in use. Second, the instrument used must be able to detect not only severe instances of thought disorder, present in psychotic populations, but also mild instances of thought slippage, since thought disorder in nonpsychotic relatives tends to be muted. Third, categories of formal thought disorder that occur infrequently in the normal population, but frequently in pathological populations, must be determined. These disorders may occur in relatives of psychotic patients.The study by Berenbaum et al