title: Thalamocortical abnormalities in auditory brainstem response patterns distinguish DSM-IV bipolar disorder type I from schizophrenia.
abstract: BACKGROUND
  Bipolar disorder type I (BP-I) belongs to a spectrum of affective disorders that are expressed in many different ways and therefore can be difficult to distinguish from other conditions, especially unipolar depression, schizoaffective disorder, schizophrenia (SZ), but also anxiety and personality disorders. Since early diagnosis and treatment have shown to improve the long-term prognosis, complementary specific biomarkers are of great value. The auditory brainstem response (ABR) has previously been applied successfully to identify specific abnormal ABR patterns in SZ and Asperger syndrome.
  
  
  METHODS
  The current study investigated the early auditory processing of complex sound stimuli e.g. forward masking, in BP-I compared to SZ patients. The ABR curves of BP-I patients (n=23) and SZ patients (n=20) were analyzed in terms of peak amplitudes and correlation with an ABR norm curve based on a non-psychiatric control group (n=20).
  
  
  RESULTS
  BP-I patients had significantly higher wave III (p=0.0062) and wave VII (p=0.0472) amplitudes compared with SZ patients. Furthermore, BP-I patients, and to a lesser extent SZ patients, showed low correlation with the norm ABR curve in the part of the curve comprising waves VI-VII.
  
  
  CONCLUSIONS
  Sample size was relatively small and study groups were not matched for age and gender.
  
  
  CONCLUSIONS
  BP-I patients showed specific aberrances, specifically in the latter part of the ABR curve, implicating abnormalities in thalamocortical circuitry. The abnormal ABR wave patterns significantly separated BP-I patients from SZ patients suggesting that ABR might serve as a biomarker for BP-I.
authors.affiliation: SensoDetect AB, Lund, Sweden.
authors.forename: Mia
authors.initials: M
authors.lastname: Sköld
authors.affiliation: SensoDetect AB, Lund, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Källstrand
authors.affiliation: SensoDetect AB, Lund, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Nehlstedt
authors.affiliation: Division of Psychiatry, Department of Clinical Sciences, Umeå University, Umeå, Sweden.
authors.forename: Annelie
authors.initials: A
authors.lastname: Nordin
authors.affiliation: SensoDetect AB, Lund, Sweden.
authors.forename: Sören
authors.initials: S
authors.lastname: Nielzén
authors.affiliation: SensoDetect AB, Lund, Sweden.
authors.forename: Jens
authors.initials: J
authors.lastname: Holmberg
authors.affiliation: Division of Psychiatry, Department of Clinical Sciences, Umeå University, Umeå, Sweden. Electronic address: rolf.adolfsson@psychiat.umu.se.
authors.forename: Rolf
authors.initials: R
authors.lastname: Adolfsson
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000503:physiopathology; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012559:Schizophrenia / Q000175:diagnosis* / Q000503:physiopathology; D013788:Thalamus / Q000503:physiopathology
keywords: Auditory brainstem response; Biomarker; Bipolar disorder; Electrophysiology; Schizophrenia; Thalamus