INDIVIDUAL-DIFFERENCES IN CEREBRAL METABOLIC PATTERNS DURING PHARMACOTHERAPY IN OBSESSIVE-COMPULSIVE DISORDER - A MULTIPLE-REGRESSION DISCRIMINANT-ANALYSIS OF POSITRON EMISSION TOMOGRAPHIC DATA

A multiple regression/discriminant analysis of positron emission tomog raphic cerebral metabolic (rCMRglc) data in 10 obsessive-compulsive di sorder (OCD) patients before and during pharmacotherapy was carried ou t to see if rCMRglc interdependencies distinguished OCD patients from controls. Before therapy, a discriminant function reflecting parietal, sensorimotor, and midbrain rCMRglc interdependencies correctly classi fied eight (80%) of the 10 patients as OCD; after therapy, six (70%) w ere classified as controls, most of whom were responders. Before thera py, rCMRglc interdependencies involving basal ganglia, thalamus, limbi c, and sensory and association cortical regions distinguished 67% of p atients who clinically responded to drug (RESP, n = 6) and 75% of pati ents who did not (NRESP, n = 4)from controls. After therapy, all RESP were classified as controls; classification of NRESP remained unchange d. The results suggest the conjunctive utility of this method to asses s individual differences in rCMRglc during pharmacotherapy, and to exp lore the neurobiology of OCD.