Gating of a novel brain potential is associated with perceptual anomalies in bipolar disorder


Corresponding author:Dr. Julie V. Patterson
Department of Psychiatry
University of California Irvine Medical Center
Building 3, Route 88
101 The City Drive
Orange, CA 92868
Fax: 714-456-5927


Patterson JV, Sandman CA, Jin Y, Kemp AS, Potkin SG, Bunney WE Jr. Gating of a novel brain potential is associated with perceptual anomalies in bipolar disorder.
Bipolar Disord 2013: 00: 000–000. © 2013 John Wiley & Sons A/S.Published by Blackwell Publishing Ltd.

Objectives:  Our laboratory recently identified the P85 gating ratio as a candidate biomarker for bipolar disorder. In order to evaluate the phenomenological significance of P85 gating, the current study examined reports of perceptual anomalies and their relationship to the P50 and P85 physiological measures of sensory gating.

Methods:  Reports of perceptual anomalies on the Structured Clinical Interview to Assess Perceptual Anomalies were compared in patients meeting DSM-IV criteria for paranoid schizophrenia (n = 66), schizoaffective disorder (n = 45), or bipolar I disorder (n = 42), and controls (n = 56), as well as their relationship with P85 and P50 gating.

Results:  The bipolar disorder group reported significantly more auditory, visual, and total anomalies than both the schizophrenia and control groups. The schizophrenia group also had more anomalies than the control group. Comparison of psychiatric subgroups revealed that the bipolar depressed, bipolar disorder with psychosis, and schizoaffective bipolar type groups reported the most anomalies compared to the other patient groups (bipolar disorder without psychosis, schizoaffective, bipolar manic). The total perceptual anomalies score and the P85 ratio significantly differentiated the bipolar disorder, schizoaffective, and paranoid schizophrenia groups from each other.

Conclusions:  These findings provide evidence of the phenomenological significance of P85. The results also yield further support not only for the P85 ratio, but also for increased reports of perceptual anomalies as possible markers for bipolar disorder.