title: Climatic factors and bipolar affective disorder.
abstract: In bipolar disorder, the factors provoking a new episode are unknown. As a seasonal variation has been noticed, it has been suggested that weather conditions may play a role. The aim of the study was to elucidate whether meteorological parameters influence the development of new bipolar phases. A group of patients with at least three previous hospitalizations for bipolar disorder was examined every 3 months for up to 3 years. At each examination an evaluation of the affective phase was made according to the Hamilton Depression Scale (HAM-D(17)), and the Bech-Rafaelsen Mania Rating Scale (MAS). In the same period, daily recordings from the Danish Meteorological Institute were received. We found no correlations between onset of bipolar episodes [defined as MAS score of 11 or more (mania) and as HAM-D(17) score of 12 or more (depression)] and any meteorological parameters. We found a statistical significant correlation between mean HAM-D(17) scores and change in mean and maximum temperature, and non-statistical significant correlations between mean MAS scores and rainfall plus atmospheric pressure, and non-statistical significant correlations between mean HAM-D(17) scores and hours of sunshine and cloudiness. Though meteorological factors may have an impact on triggering new episodes in bipolar patients, they do not constitute a dominant cause.
authors.affiliation: Psychiatric Center-Rigshospitalet, Clinic of Affective Disorders, Hans Kirks Vej 6, Copenhagen N, Denmark. ellen.margrethe.christensen@rh.regionh.dk
authors.forename: Ellen Margrethe
authors.initials: EM
authors.lastname: Christensen
authors.forename: Jens Knud
authors.initials: JK
authors.lastname: Larsen
authors.forename: Annette
authors.initials: A
authors.lastname: Gjerris
authors.forename: Linda
authors.initials: L
authors.lastname: Peacock
authors.forename: Marianne
authors.initials: M
authors.lastname: Jacobi
authors.forename: Ellen
authors.initials: E
authors.lastname: Hassenbalch
mesh_terms: D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D002980:Climate; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D012720:Severity of Illness Index