STEREOTYPY, SCHIZOPHRENIA AND DOPAMINE D-2 RECEPTOR-BINDING IN THE BASAL GANGLIA

Animal models suggest a relationship between disturbed striatal dopami nergic function and stereotyped behaviour. Several studies show increa sed stereotypy in schizophrenic patients compared to normal controls. We investigated the performance of 12 antipsychotic-drug-free schizoph renic patients, and 15 healthy control subjects on a neuropsychologica l measure of stereotypy - the two-choice guessing task - and correlate d this with in vivo striatal dopamine D, receptor binding, as measured by I-123-iodobenzamide single photon emission tomography. Patients an d controls did not differ with respect to the measures of stereotypy d erived from the task. However, there was a significant correlation bet ween one of these measures (RR Information) and the degree of striatal D, receptor binding asymmetry in the patient group only. In view of r esearch connecting striatal and frontal lesions with stereotypy in ani mals and cognitive inflexibility in humans, these data could suggest a similar disturbance underlying the phenomenon in schizophrenia.