Seasonal variations in mood and behaviour: epidemiological findings in the north tropics.
BACKGROUND
There has been no epidemiological study of seasonal affective disorder (SAD) in the north tropics.


METHODS
The investigators randomly mailed the Seasonal Pattern Assessment Questionnaire (SPAQ) to 520 residents in Chiang Mai Municipality.


RESULTS
The prevalence rates of summer SAD, subsyndromal summer SAD and winter SAD are 6.19%, 8.25% and 1.03%, respectively.


CONCLUSIONS
The epidemiological study of SAD in the north tropics finds a high prevalence of summer SAD, low prevalence of winter SAD and the correlation between 'feel worst' response and temperature.


CONCLUSIONS
The reliability and validity of SPAQ in diagnosing summer SAD is probably low. The response rate from the studied sample is low.


CONCLUSIONS
The prevalence of summer SAD in the tropics is much higher than that in the temperate zone and may relate to temperature.
Department of Psychiatry, Chiang Mai University, Muang, Thailand. mdimsrsp@chiangmai.ac.th
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Srisurapanont
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Intaprasert
D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016574:Seasonal Affective Disorder / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology*; D012621:Seasons; D011795:Surveys and Questionnaires; D013785:Thailand / Q000453:epidemiology; D014329:Tropical Climate