An examination of seasonality experienced by Australians living in a continental temperate climate zone.
BACKGROUND
To date, there has been only limited information on factors associated with seasonal changes in mood and behaviour experienced by a random sample of Australians living in a continental temperate climate region. This paper identifies socio-demographic, psychological and personality factors associated with reporting higher levels of seasonality.


METHODS
Information on seasonal change using the Seasonal Pattern Assessment Questionnaire (SPAQ) was obtained from 7485 persons in three age groups. Age and sex differences in seasonality scores were examined. Those meeting probable caseness for seasonal affective disorder were identified and compared with less-seasonal participants on a range of state and trait measures.


RESULTS
Levels of seasonality reported by survey participants were comparable to those reported in northern hemisphere studies of randomly selected community samples. However, these levels were significantly lower than other key studies outside Australia and previous Australian findings. Compared with less-seasonal participants, those reporting seasonal change had more current depressive and anxiety symptoms and higher levels of negative affect, regardless of season of interview.


CONCLUSIONS
This study is likely to over-estimate the number of participants who meet requirements for caseness for seasonal affective disorder.


CONCLUSIONS
Levels of seasonality experienced by a random sample of Australians living in a temperate climate are comparable to those reported by similar groups in the northern hemisphere. Importantly, this study found that those experiencing higher levels of seasonality had significantly more current depressive symptoms than less-seasonal participants across all seasons. These results raise questions about the usefulness of the SPAQ as a measure of seasonal variation in mood and behaviour.
Parslow
Ruth A
RA
Centre for Mental Health Research, Australian National University, Acton, ACT 2601, Australia. ruth.parslow@anu.edu.au
Jorm
Anthony F
AF
Butterworth
Peter
P
Jacomb
Patricia A
PA
Rodgers
Bryan
B
D000328:Adult; D001315:Australia / Q000453:epidemiology; D002980:Climate; D015331:Cohort Studies; D003863:Depression / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D016574:Seasonal Affective Disorder / Q000453:epidemiology*; D011795:Surveys and Questionnaires