An initial report of a new biological marker for bipolar disorder: P85 evoked brain potential.

Full Abstract

OBJECTIVES: Progress toward understanding the neurobiological and genetic underpinnings of bipolar disorder has been limited by the scarcity of potential biological markers that predict its occurrence. A measure of the integrity of brain inhibitory function, sensory gating, measured using the amplitude of the evoked potential at 50 ms to the first of two paired clicks divided by the response to the second, has been characterized as a biological marker for schizophrenia. Currently, no such biological marker exists for bipolar disorder. The goal of this research was to determine how gating of an auditory brain potential at 85 ms (P85), not previously examined in sensory gating studies, differentiated control and patient groups. METHODS: P50 and P85 auditory evoked potentials were collected from individuals diagnosed with schizoaffective disorder (n = 45), paranoid schizophrenia (n = 66), and bipolar I disorder (n = 42) using DSM-IV criteria and the Structured Clinical Interview for DSM-IV; and from 56 healthy controls. RESULTS: The P85 gating ratio was significantly larger in the bipolar disorder group compared to each of the other groups (F(3,204) = 5.47, p = 0.001, and post-hoc tests). The P50 gating ratio was significantly larger for the schizoaffective group than for the control group (F(3,204) = 2.81, p = 0.040), but did not differ from the ratio for the schizophrenia, paranoid type (p = 0.08) and bipolar groups. CONCLUSIONS: The previously unstudied P85 gating ratio may provide a new marker specific to bipolar disorder. The findings will promote further studies to investigate the unique contribution of this measure as an endophenotype.

Author information

Author/s: Patterson, Julie V (JV); Sandman, Curt A (CA); Ring, Alex (A); Jin, Yi (Y); Bunney, William E (WE);

Affiliation: Department of Psychiatry and Human Behavior, University of California at Irvine, Irvine, California 92868, USA. jvpatter(-atsign-)uci.edu

Journal and publication information

Publication Type: Journal Article

Journal: Bipolar disorders (Bipolar Disord), published in Denmark. (Language: eng)

Reference: 2009-Sep; vol 11 (issue 6) : pp 596-609

Dates: Created 2009/08/19; Completed 2009/11/05;

PMID: 19689502, status: MEDLINE (last retrieval date: 11/5/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

External Links for this article
(including full text providers, if available):

Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.

This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.