It looks like deficiency of sunlight causes law spirits and lack of energy. Some people notice that it is hard for them to get up in the morning and be active, they gain more weight and communicate less when nights become darker and longer. Is it a standard behavior in winter or something is wrong?Seasonal affective disorder (SAD) is a case of recurrent depressive disorder, included in the International Classification of Diseases with the number “F33”. The Diagnostic and Statistical Manual of Mental Disorders considers SAD as an isolated occasion of either clinical depression or bipolar disorder. It should be noticed, that a mental physician must determine an adequate diagnosis after detailed questionnaires are filled in. The psychiatrist from Oslo Andres Magnusson, one of the most prominent researchers of SAD, outlines the following criteria that help us to determine the depression as seasonal:
- mood disorder starts at the same 90-day period of the year during at least 3 years;
- disturbance disappear also at the same months.
SAD researchIf you think that it is absolutely normal to feel sadness in winter and wait for the spring under your blanket with a cup of hot tea, probably, you belong to the nation that is genetically adapted to long dark nights. Therefore, you are more immune to SAD, according to the research of Barry Whitehead. Whitehead explores SAD as a complex event generated by geographical, cultural and genetic factors. As for genetics, people of the Northern Europe are more resistant to seasonal disturbance because their traditions are adapted to the dark and cold period: they have many social events, they supplement their diet with fatty dishes and they put candles which create a pleasant natural light. That is why expats from Southern Europe might feel SAD symptoms in Norway, for example, while locals would not treat it as a serious disorder. Another important finding of the study is connection between SAD and latitude. It is discovered that the average rate of SAD in high latitudes is 20 higher than the average rate of SAD in low latitudes. It is hard for people not only to get along during short periods of daylight, but also to adjust to week-to-week changes of phases. According to the research, the prevalence of SAD depends on the latitude. For instance, 12.5% of population suffer from SAD in northern New York, while there are only 1.4% in Florida. Raymond Cochrane who has compared despondence and anxiety of Asian women having moved to the UK from hot countries and native Englishwomen has explored the same tendency. The ladies from Asia got 8.41 points in the questionnaire in winter, while the European women had 4.8 points.
The more northern you country is, the more prone to SAD you are. What is the latitude of your home? Have you ever noticed any symptoms of SAD? Despondence and activity decrease at a definite period of year? Anxiety and irritation during certain months? Maybe, it is time to make a SAD test!