Ms. Chen recounted that in the past three years, every autumn and winter, she inexplicably experienced bad mood, disinterest in things, often thoughtlessness, decreased work efficiency, unwillingness to move around, reluctance to interact, panic, insomnia and other symptoms. However, with the change of seasons, her mood improved in the spring and summer, and these phenomena gradually disappeared. The psychologist gave her a psychological test and the result showed that the depression index was 0.63, which is moderate depression. Based on the description of the symptoms and the diagnostic criteria for psychological disorders, the psychiatrist concluded that she was suffering from a psychological disorder called “winter depression disorder”. When winter comes, the number of patients with depressive disorder in the psychology department of the hospital is significantly higher than in other seasons. Scholars have been paying attention to this phenomenon of increasing number of depression in winter for a long time. They named it as “seasonal affective disorder” or “winter depression disorder”. However, medical research has not yet come to a definite conclusion as to why depression is more frequent in winter. Most experts believe that it is related to changes in human physiological activities such as metabolism, endocrine system, and neurobiochemistry due to winter climate and low sun exposure. It is also believed that depression is triggered in susceptible people due to environmental conditions such as cold, cloudy and foggy winter days, and lack of life in nature, as well as negative factors such as people going out and socializing less during this season. So, what should I do if I suffer from winter depression disorder? Patients with mild winter depression disorder can make self-psychological and behavioral adjustments, such as actively adjusting their negative perceptions and feelings; frequently participating in interpersonal activities to enhance interpersonal communication and exchange; getting more sunshine and doing outdoor sports; trying to do things that usually interest them and experiencing the joy of life from them. For patients with major depressive disorder who have negative anhedonia, they should seek help from psychologists in the psychology department and take antidepressants for treatment if necessary.