Development of a picture-preference measure of thought disorder

In order to create a test of thought disorder which would measure the whole range of thinking disturbances and which would be free of influence by factors irrelevant to thought disorder, the authors devised a 31-item picture-preference scale. For each item the subject is asked to choose between a picture representing absurd, illogical or regressive thinking, and a picture representing better controlled and more adaptive thinking. Each of the items, shown by slide-projector, is exposed for 10 S. The sample included 70 consecutively admitted psychiatric in-patients and 151 adults who were not patients. The mean score of the patients is significantly higher than the mean of the non-patients. We also found a significant correlation (r = 0.38) between the thought-disorder scale and a summation of the ratings on the Brief Psychiatric Rating Scale that are relevant to thought disorder. Those patients whom the interviewer rated as showing thought disorder have significantly higher scores than the other patients (t = 3.49, d.f. = 68, P < 0.001). Finally, we found a significant correlation, r = 0.26, between the scores on the Picture-Preference Test of Thought Disorder and scores on the psychotic tendencies scale of the Differential Personality Inventory, among the psychiatric patients.