Divergent backward masking performance in schizophrenia and bipolar disorder: Association with COMT

AbstractSchizophrenia has been reliably associated with impairments in backward masking performance, while bipolar disorder has less consistently been tied to such a deficit. To examine the genetic determinants of visual perception abnormalities in schizophrenia and bipolar disorder, this study evaluated the diagnostic specificity of backward masking performance deficits and whether masking deficits were associated with catechol‐O‐methyl transferase (COMT) genotype. A location‐based backward masking task, which equated participants on the perceptual intensity of stimuli, was completed by 41 schizophrenia outpatients, 28 bipolar outpatients, and 43 nonpsychiatric controls. COMT genotype data were available for 39 schizophrenia outpatients, 28 bipolar outpatients, and 20 nonpsychiatric controls. Schizophrenia patients demonstrated impaired backward masking performance compared to controls and bipolar patients. A group by COMT genotype interaction was detected with schizophrenia Met homozygotes performing more poorly than control and bipolar Met homozygotes, and worse than Val homozygote and heterozygote schizophrenia patients. This study provides novel evidence for differential effec