title: Stressful life events in bipolar I and II disorder: cause or consequence of mood symptoms?
abstract: BACKGROUND
  Life events are assumed to be triggers for new mood episodes in bipolar disorder (BD). However whether life events may also be a result of previous mood episodes is rather unclear.
  
  
  METHODS
  173 bipolar outpatients (BD I and II) were assessed every three months for two years. Life events were assessed by Paykel׳s self-report questionnaire. Both monthly functional impairment due to manic or depressive symptomatology and mood symptoms were assessed.
  
  
  RESULTS
  Negative life events were significantly associated with both subsequent severity of mania and depressive symptoms and functional impairment, whereas positive life events only preceded functional impairment due to manic symptoms and mania severity. These associations were significantly stronger in BD I patients compared to BD II patients. For the opposite temporal direction (life events as a result of mood/functional impairment), we found that mania symptoms preceded the occurrence of positive life events and depressive symptoms preceded negative life events.
  
  
  CONCLUSIONS
  The use of a self-report questionnaire for the assessment of life events makes it difficult to determine whether life events are cause or consequence of mood symptoms. Second, the results can only be generalized to relatively stable bipolar outpatients, as the number of severely depressed as well as severely manic patients was low.
  
  
  CONCLUSIONS
  Life events appear to precede the occurrence of mood symptoms and functional impairment, and this association is stronger in BD I patients. Mood symptoms also precede the occurrence of life event, but no differences were found between BD I and II patients.
authors.affiliation: PsyQ The Hague, Department of Mood Disorders, The Hague, The Netherlands.
authors.forename: M A
authors.initials: MA
authors.lastname: Koenders
authors.affiliation: Leiden University Medical Center, Department of Psychiatry, Leiden, The Netherlands.
authors.forename: E J
authors.initials: EJ
authors.lastname: Giltay
authors.affiliation: PsyQ The Hague, Department of Mood Disorders, The Hague, The Netherlands.
authors.forename: A T
authors.initials: AT
authors.lastname: Spijker
authors.affiliation: PsyQ The Hague, Department of Mood Disorders, The Hague, The Netherlands; Department of Clinical Health and Neuropsychology, Leiden University, Leiden, The Netherlands.
authors.forename: E
authors.initials: E
authors.lastname: Hoencamp
authors.affiliation: Department of Clinical Health and Neuropsychology, Leiden University, Leiden, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: Spinhoven
authors.affiliation: Department of Clinical Health and Neuropsychology, Leiden University, Leiden, The Netherlands.
authors.forename: B M
authors.initials: BM
authors.lastname: Elzinga
mesh_terms: D000328:Adult; D000339:Affect; D001714:Bipolar Disorder / Q000523:psychology*; D005260:Female; D006801:Humans; D008016:Life Change Events; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012720:Severity of Illness Index
keywords: Bipolar disorder; Depression; Life events; Mania