Sylvia B Guillory1, Eva Velthorst1, Peter Bachman2, Aysenil Belger3, Ricardo Carrión4, Erica Duncan5, Jason Johannesen6, Margaret Niznikiewicz7, Kristin Cadenhead8, Jennifer Foss-Feig1, NAPLS Consortium, Daniel H. Mathalon9; 1Icahn School of Medicine at Mount Sinai, 2University of Pittsburgh, 3University of North Carolina, 4Zucker Hillside Hospital, 5Emory University, 6Yale University, 7Harvard Medical School, 8University of California, San Diego, 9University of California, San Francisco
Autism spectrum disorder (ASD) and schizophrenia are distinct disorders. However, atypical sensory and attentional processing characterizes both, and psychosis symptoms exist disproportionally in ASD. Electrophysiological markers that characterize schizophrenia, including P300 and mismatch negativity (MMN) amplitude reductions, are present in individuals at clinical high-risk (CHR) for psychosis. Whether these markers are: present in ASD individuals showing CHR profiles and/or predictive of conversion is unknown. We investigated P300 and MMN response and sensitivity to psychosis conversion across CHR groups with (CHR/ASD+) and without(CHR/ASD−) comorbid ASD. Electrophysiological data were analyzed from 305 NAPLS-2 CHR patients (14 CHR/ASD+; 291 CHR/ASD−). We examined P300 amplitude to infrequent Target(10%) and Novel distractor(10%) stimuli from visual and auditory oddball tasks, and MMN response for duration(5%), frequency(5%), and duration+frequency(5%) deviants. P300 amplitude to Novel visual stimuli was smaller in CHR/ASD− converters(n=71) than CHR/ASD− non-converters(n=220), but larger in CHR/ASD+ converters(n=4) than CHR/ASD+ non-converters(n=10) (Modality×ASD×Converter Interaction, F=3.57;p=.06). For auditory and visual Target stimuli, whereas P300 amplitude was similar for CHR/ASD+ non-converters and all CHR/ASD− individuals, CHR/ASD+ converters had larger P300 amplitudes (ASD×Converter interaction, F=12.12;p=.001). For MMN, there were no significant amplitude differences between groups (Conversion,p=0.31; ASD,p=0.57) or deviant type (p=0.56). Results revealed dissociable P300 amplitude profiles to visual and auditory target and novel stimuli in CHR patients that differentially predicted conversion to psychosis, depending on ASD status. MMN did not differ by ASD status. These findings suggest attentional orienting is differentially affected in CHR patients with ASD, whereas pre-attentive sensory memory is similar in CHR with and without ASD.
