title: Gender differences in the heritability of seasonal mood change.
abstract: The study estimated gender differences in the magnitude of genetic and environmental influence in seasonal mood change. The self-report Seasonal Pattern Assessment Questionnaire (SPAQ) was completed by 339 volunteer reared-together twinpairs (187 monozygotic pairs, 152 dizygotic pairs) and analysed using biometric genetic models. The SPAQ yields a global seasonality score (GSS) which is an index of change in sleep patterns, social activities, mood, weight, appetite, and energy level. The GSS was significantly heritable among males and females, estimated to account for 69% and 45% of the total variance, respectively. For the individual symptoms, changes in sleep patterns, social activities, mood, appetite, and energy levels were accounted for primarily by additive genetic effects in both males (median, 45.5%) and females (median, 30.5%). For both sexes, weight changes were not heritable. Sex-by-genotype analyses suggested that the genetic factors influencing female seasonality may not be the same as those influencing male seasonality.
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, Canada. kjang@unixg.ubc
authors.forename: K L
authors.initials: KL
authors.lastname: Jang
authors.forename: R W
authors.initials: RW
authors.lastname: Lam
authors.forename: W J
authors.initials: WJ
authors.lastname: Livesley
authors.forename: P A
authors.initials: PA
authors.lastname: Vernon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004200:Diseases in Twins / Q000235:genetics* / Q000523:psychology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008957:Models, Genetic; D010555:Personality Inventory; D012306:Risk; D016574:Seasonal Affective Disorder / Q000175:diagnosis / Q000235:genetics* / Q000523:psychology; D012737:Sex Factors; D012931:Social Environment; D014429:Twins, Dizygotic / Q000235:genetics / Q000523:psychology; D014430:Twins, Monozygotic / Q000235:genetics / Q000523:psychology