Bipolar Research Today is a free monthly online journal that collates and summarizes the latest research about Bipolar, including details on bipolar disorder, symptoms, treatment, depression, medication.

Normal levels of prepulse inhibition in the euthymic phase of bipolar disorder.

Barrett SL, Kelly C, Watson DR, Bell R, King DJ

Department of Psychology, University of Ulster, Jordanstown Campus, Co. Antrim, UK. s.barrett@ulster.ac.uk

BACKGROUND:Deficits in prepulse inhibition (PPI) of the acoustic startle response have been suggested as a potentially useful endophenotype for schizophrenia spectrum disorders and may explain certain symptoms and cognitive deficits observed in the psychoses. PPI deficits have also been found in mania, but it remains to be confirmed whether this dysfunction is present in the euthymic phase of bipolar disorder.METHOD: Twenty-three adult patients with DSM-IV bipolar disorder were compared to 20 controls on tests of acoustic startle reactivity and PPI of the startle response. Sociodemographic and treatment variables were recorded and symptom scores assessed using the Hamilton Depression Inventory and the Young Mania Rating Scale.RESULTS:Overall, the patient and control groups demonstrated similar levels of startle reactivity and PPI, although there was a trend for the inter-stimulus interval to differentially affect levels of PPI in the two groups.CONCLUSIONS: In contrast to bipolar patients experiencing a manic episode, general levels of PPI were normal in this euthymic sample. Further studies are required to confirm this finding and to determine the mechanisms by which this potential disruption/normalization occurs. It is suggested that an examination of PPI in a high-risk group is required to fully discount dysfunctional PPI as a potentially useful endophenotype for bipolar disorder.

Published 22 November 2005 in Psychol Med, 35(12): 1737-46.
Full-text of this article is available online (may require subscription).

© 2004-2008 Bipolar Research Today. All Rights Reserved.