title: Behavioral Approach System and Behavioral Inhibition System sensitivities and bipolar spectrum disorders: prospective prediction of bipolar mood episodes.
abstract: OBJECTIVE
  Research has found that bipolar spectrum disorders are associated with Behavioral Approach System (BAS) hypersensitivity and both unipolar and bipolar depression are associated with high Behavioral Inhibition System (BIS) sensitivity, but prospective studies of these relationships are lacking. We tested whether BAS and BIS sensitivities prospectively predicted the time to new onsets of major depressive and hypomanic and manic episodes in bipolar spectrum individuals.
  
  
  METHODS
  We followed 136 bipolar II or cyclothymic and 157 demographically matched normal control individuals prospectively for an average of 33 months. Participants completed the BIS/BAS scales and symptom measures at Time 1 and semi-structured diagnostic interviews every four months of follow-up.
  
  
  RESULTS
  The bipolar spectrum group exhibited higher Time 1 BAS, but not BIS, scores than the normal controls, controlling for Time 1 symptoms. Among bipolar spectrum participants, high BAS sensitivity prospectively predicted a shorter time to onset of hypomanic and manic episodes, whereas high BIS sensitivity predicted less survival time to major depressive episodes, controlling for initial symptoms.
  
  
  CONCLUSIONS
  Consistent with the BAS hypersensitivity model of bipolar disorder, a highly responsive BAS provides vulnerability to onsets of (hypo)manic episodes. In addition, a highly sensitive BIS increases risk for major depressive episodes.
authors.affiliation: Psychology Department, Temple University, Philadelphia, PA 19122, USA. lalloy@temple.edu
authors.forename: Lauren B
authors.initials: LB
authors.lastname: Alloy
authors.forename: Lyn Y
authors.initials: LY
authors.lastname: Abramson
authors.forename: Patricia D
authors.initials: PD
authors.lastname: Walshaw
authors.forename: Alex
authors.initials: A
authors.lastname: Cogswell
authors.forename: Louisa D
authors.initials: LD
authors.lastname: Grandin
authors.forename: Megan E
authors.initials: ME
authors.lastname: Hughes
authors.forename: Brian M
authors.initials: BM
authors.lastname: Iacoviello
authors.forename: Wayne G
authors.initials: WG
authors.lastname: Whitehouse
authors.forename: Snezana
authors.initials: S
authors.lastname: Urosevic
authors.forename: Robin
authors.initials: R
authors.lastname: Nusslock
authors.forename: Michael E
authors.initials: ME
authors.lastname: Hogan
mesh_terms: D000328:Adult; D000339:Affect; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000453:epidemiology; D003865:Major Depressive Disorder / Q000453:epidemiology; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011596:Psychomotor Disorders / Q000453:epidemiology* / Q000523:psychology