title: Influence of seasonal variation in mood and behavior on cognitive test performance among young adults.
abstract: BACKGROUND
  Seasonal variations in mood and behavior are common among the general population and may have a deteriorating effect on cognitive functions.
  
  
  OBJECTIVE
  In this study the effect of seasonal affective disorder (SAD-like symptoms) on cognitive test performance were evaluated in more detail.
  
  
  METHODS
  The data were derived from the study Mental Health in Early Adulthood in Finland. Participants (n = 481) filled in a modified Seasonal Pattern Assessment Questionnaire (SPAQ) and performed cognitive tests in verbal and visual skills, attention and general intelligence.
  
  
  RESULTS
  SAD-like symptoms, especially regarding the seasonal variations in weight and appetite, had a significant effect on working memory (Digit Span Backward, P = 0.008) and auditory attention and short-term memory (Digit Span Forward, P = 0.004). The seasonal variations in sleep duration and mood had an effect on auditory attention and short-term memory (Digit Span Forward, P = 0.02 and P = 0.0002, respectively). The seasonal variations in social activity and energy level had no effect.
  
  
  CONCLUSIONS
  Seasonal changes in mood, appetite and weight have an impairing effect on auditory attention and processing speed. If performance tests are not to repeated in different seasons, attention needs to be given to the most appropriate season in which to test.
authors: Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland. ilona.merikanto@helsinki.fi
authors: Ilona
authors: I
authors: Merikanto
authors: Tuuli
authors: T
authors: Lahti
authors: Anu E
authors: AE
authors: Castaneda
authors: Annamari
authors: A
authors: Tuulio-Henriksson
authors: Terhi
authors: T
authors: Aalto-Setälä
authors: Jaana
authors: J
authors: Suvisaari
authors: Timo
authors: T
authors: Partonen
mesh_terms: D000293:Adolescent; D000328:Adult; D000339:Affect; D001066:Appetite / Q000502:physiology; D001288:Attention / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003071:Cognition / Q000502:physiology*; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology; D011594:Psychometrics; D016574:Seasonal Affective Disorder / Q000175:diagnosis / Q000523:psychology*; D012621:Seasons; D012890:Sleep / Q000502:physiology; D011795:Surveys and Questionnaires; D055815:Young Adult