title: Aberrant emotional processing in posterior cortical midline structures in bipolar II depression.
abstract: Bipolar II depression is a serious and disabling illness associated with significant impairment and high rates of suicide attempts. However, mechanisms underlying emotional dysregulation in this condition are poorly characterized. The goal of this work was to investigate one component of emotional processing in this disorder, brain activation associated with exposure to emotional faces. Functional MRI was used to study 16 unmedicated male subjects with bipolar II depression and 19 healthy male controls. The activation paradigm exposed subjects to happy, fearful and neutral faces. The two key findings of this study were as follows. First, bipolar subjects demonstrated significantly decreased activation in response to happy facial expression in the left posterior cortical midline structures (CMS) and frontal cortex. Second, depression severity was positively correlated with activation of the posterior CMS and other regions. Our results suggest that mechanisms involving CMS dysfunction may play a role in the neurobiology of bipolar II depression as has been demonstrated for unipolar illness. Further investigations of CMS function in bipolar spectrum disorders are warranted.
authors.affiliation: George E. Wahlen Veterans Affairs Medical Center, 500 Foothill Blvd, Salt Lake City, UT 84148, United States. wmarchand@me.com
authors.forename: William R
authors.initials: WR
authors.lastname: Marchand
authors.forename: James N
authors.initials: JN
authors.lastname: Lee
authors.forename: Cheryl
authors.initials: C
authors.lastname: Garn
authors.forename: John
authors.initials: J
authors.lastname: Thatcher
authors.forename: Phillip
authors.initials: P
authors.lastname: Gale
authors.forename: Sebastian
authors.initials: S
authors.lastname: Kreitschitz
authors.forename: Susanna
authors.initials: S
authors.lastname: Johnson
authors.forename: Nicole
authors.initials: N
authors.lastname: Wood
mesh_terms: D000328:Adult; D000679:Amygdala / Q000503:physiopathology; D001714:Bipolar Disorder / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D001921:Brain / Q000503:physiopathology; D003201:Computers; D004644:Emotions / Q000502:physiology*; D005149:Facial Expression; D005239:Fear; D005260:Female; D006179:Gyrus Cinguli / Q000503:physiopathology; D006240:Happiness; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012984:Software; D055815:Young Adult