A cross-sectional study of retrospectively reported seasonality in native and non-native residents of Chukotka and Turkmenistan

ABSTRACT

Seasonality represents a response of human mood, physiology, and behavior to annual variations in natural and social environment. A strong seasonal response is expected in non-native than native residents of such regions as Turkmenistan that is characterized by high air temperature in summer and Chukotka that is characterized by high-amplitude annual variation in both air temperature and day length. Seasonality was retrospectively reported by 732 residents of these regions. Self-reports on sleep-wake traits and mental and physical health were analyzed as possible confounding variables. The expectation of stronger seasonality in non-native residents was confirmed only for Chukotka samples. However, the native–non-native seasonality differences in this region paralleled the differences in several health scores, while native–non-native health difference in Turkmenistan was found to be non-significant. Given the possible role of such confounding factor as poor health in producing higher self-reported seasonality scores, caution must be taken when the conclusion is drawn from the results suggesting a reduced degree and severity of seasonality in native residents of Chukotka as compared to other native and non-native residents of the two regions.

KEYWORDS:

• Seasonal affective disorder
• depression
• health
• sleep-wake pattern
• aboriginals
• newcomers

Acknowledgments

The author is indebted to Dr John Booker for his participation in translation and cross-validation of the applied questionnaires and to Dr Konstantin Danilenko, Dmitriy Zolotarev (Heffele), and Dr Vladislav Palchikov for their valuable help in collecting these questionnaire data.

Disclosure statement

No potential conflict of interest was reported by the author.

Additional information

Funding

The study was supported by grants from the Russian Foundation for Basic Research (number 07-06-00263-а, number 10-06-00114-а, number 13-06-00042-a, and number 16-06-00235-a) and the Russian Foundation for Humanities (number 06-06-00375-a, number 12-06-18001-e, and number 15-06-10403-a).