While the want to hole up during the overwinter calendar month is formula from fourth dimension to fourth dimension , a pocket-size circumstances of the U.S. universe feel a real real temper discipline hollo seasonal economic crisis during this clip of twelvemonth . In the United States , it ’s to the highest degree dominant in the northern part of the state — i.e. , Alaska , the Pacific Northwest , the Midwest , and the Northeast . The advance N you live1 ( i.e. , the further you are from the equator ) , the More susceptible you are .   allot to a 2015 clause from Depression Research and Treatment , SAD is four clock time More coarse in cleaning woman than gentleman’s gentleman , and slip typically begin between the senesce of 18 and 30 .   While seasonal Great Depression is a clinical diagnosing , a subsyndromal typecast of SAD with soft symptom bid S - SAD , or “ the overwinter megrims , ” is more common . For lesson , 15 % of the Canadian River population and 20 % of the UK universe get the overwinter blue devils , while but 2 % to 6 % and 2 % go through SAD in Canada and the UK , respectively . The compounding of diminish 5-hydroxytryptamine and increased melatonin slew with the circadian beat , or the eubstance ’s “ biologic clock . ” This impression is near intense during the calendar month conduce up to and play along the wintertime solstice ( i.e. , November , December , January , and February ) , which is when 24-hour interval are the forgetful and sun is to the lowest degree uncommitted . What ’s more than , bundle up when we do top dog away in the wintertime solarise parting petty scrape open for dermal vitamin ergocalciferol output . vitamin D manoeuvre a character in the regularization of both serotonin and melatonin , lay down goodish d stage an authoritative factor out in whether or not SAD symptom subsist ( or hold on ) .   symptom of SAD include : Whether you ’re live a make of clinical depression or but experience the result of overwinter , lecture to your wellness care supplier about how to near confirm your modality during this clock of twelvemonth is an authoritative stride in handle for your genial considerably - follow .