title: Risk and resilience markers in bipolar disorder: brain responses to emotional challenge in bipolar patients and their healthy siblings.
abstract: OBJECTIVE
  The authors previously identified depression-specific differences in brain responses to an emotional challenge in patients with bipolar and unipolar mood disorder. In this study, potential markers of bipolar risk and resilience were examined in a new cohort of lithium-responsive bipolar patients and their healthy siblings.
  
  
  METHODS
  Changes in regional cerebral blood flow (rCBF) were measured with [(15)O]water positron emission tomography after induction of transient sadness in nine euthymic lithium responders and nine healthy siblings. The patterns of change in these groups were compared, and then they were contrasted with previous findings on bipolar responders to valproate.
  
  
  RESULTS
  Common to all three groups with induced sadness were rCBF increases in the dorsal/rostral anterior cingulate and anterior insula and decreases in the orbitofrontal and inferior temporal cortices. Distinguishing the groups were decreases in the medial frontal cortex in the patients but an increase in this region in the siblings.
  
  
  CONCLUSIONS
  Common changes with emotional challenge were identified in bipolar patients and their healthy siblings. These were not seen previously in healthy subjects without a family history of mood disorder, suggesting a potential marker of bipolar risk. The siblings' unique increases in the medial frontal cortex appear to identify a compensatory response in this at-risk group, as this pattern was not seen previously in healthy subjects without depression risk factors. This differential change pattern in patients and their siblings highlights the role of the anterior cingulate and medial frontal regions in mediating resiliency and vulnerability in bipolar disorder families.
authors.affiliation: Centre for Addiction and Mental Health, University of Toronto, Toronto, Ontario, Canada. stephanie.krueger@uniklinikum-dresden.de
authors.forename: Stephanie
authors.initials: S
authors.lastname: Krüger
authors.forename: Martin
authors.initials: M
authors.lastname: Alda
authors.forename: L Trevor
authors.initials: LT
authors.lastname: Young
authors.forename: Kim
authors.initials: K
authors.lastname: Goldapple
authors.forename: Saghar
authors.initials: S
authors.lastname: Parikh
authors.forename: Helen S
authors.initials: HS
authors.lastname: Mayberg
mesh_terms: D000328:Adult; D015415:Biomarkers; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000188:drug therapy; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000187:drug effects; D015331:Cohort Studies; D003866:Depressive Disorder / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000188:drug therapy; D004644:Emotions / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging; D006179:Gyrus Cinguli / Q000098:blood supply / Q000000981:diagnostic imaging; D006801:Humans; D008094:Lithium / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D010104:Oxygen Radioisotopes; D049268:Positron-Emission Tomography; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012307:Risk Factors; D035781:Siblings / Q000523:psychology*; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging; D014635:Valproic Acid / Q000494:pharmacology / Q000627:therapeutic use; D014867:Water
chemical_list: D015415:Biomarkers; D010104:Oxygen Radioisotopes; D014867:Water; D014635:Valproic Acid; D008094:Lithium