Khaberni - Many face a noticeable decline in mood as the winter season continues, driven by weeks of extreme cold and the absence of sunlight brightness; where some complain of constant fatigue, lack of energy, and motivation, even without suffering from visible seasonal illnesses.
Dietmar Winkler, from the University Hospital for Psychiatry and Psychotherapy in Vienna, explained that the lack of daylight for several months depletes both physical and psychological reserves, affirming that the combination of cold weather with fewer sunshine hours intensifies symptoms among those most susceptible to these effects.
Winkler discussed what is called "expectation disappointment," which arises from the psychological anticipation of spring versus the ongoing gloomy and cold winter weather.
On his part, sleep researcher and specialist in chronobiology, Dieter Kunz from Charité University Hospital in Berlin, mentioned that humans enter an "energy saving mode" starting from autumn.
He pointed out that the symptoms of winter depression usually peak towards the end of the season, where studies have shown a decrease in the secretion rate of the hormone "serotonin" in the brain by about 20 to 30% during the winter.
Kunz noted that previous assumptions which considered artificial light to have no effect on the biological clock—due to its weakness compared to natural light—were "mistaken."
A study conducted by his team on adults in a sleep lab in Berlin revealed that humans tend to sleep an additional hour in winter if given the chance, away from restrictions.
Kunz also warned that work and school schedules do not accommodate these seasonal changes, forcing many to sleep about an hour less, which he described as an unhealthy matter that negatively affects performance and overall mood directly. He added that "deep sleep" is linked to the length of the day, while other sleep stages are affected by external temperature; if temperatures exceed the freezing point, it may take 14 days for the actual duration of sleep in different stages to decrease.
In addition to the usual seasonal symptoms, more severe cases classified medically as "Seasonal Affective Disorder" emerge.
According to a review study published in the "Journal of Psychiatric Research," the percentage of those affected by this disorder ranges between 1 and 10% depending on geographical location, with significant impact noted among women and youth.
