Ever noticed someone you love pulling away as fall or winter approaches? Maybe they seem more irritable or low. They choose to stay indoors, skip gatherings, and sleep more than usual. This is not what they deliberately choose to do. The change of season can bring real shifts in the body and brain that shape mood, energy, and behavior. The researchers have given this shift of behavior a name called as “seasonal affective disorder” (SAD).

Seasonal Affective Disorder Is More Than Winter Blues

It is a mood disorder characterized by recurrent depressive episodes that align with seasonal changes, particularly during fall and winter. It entered the medical literature in 1984 when Rosenthal and colleagues described 29 patients whose depressions returned at the same time every year. Many slept more, ate more, craved for carbohydrates, and the team began testing light therapy as a treatment. Since then, SAD has been recognized as a recurring form of depression that occurs in different seasons and deserves the same understanding we would offer for other mental health conditions. It usually affects women and younger individuals. The changes in daylight hours during the autumn and winter may be responsible for the disruptions of the body’s internal clock also called as circadian rhythm, leading to mood disturbances. Seasonal changes may also affect the functioning of neurotransmitters, chemical messengers in brain necessary for healthy brain functioning, particularly serotonin, dopamine, and norepinephrine, which are involved in regulating mood and other functions in body.

Clinical features worth noticing

SAD is characterized by a range of depressive symptoms that recur seasonally. The symptoms typically include both classical and atypical manifestations which can significantly affect daily functioning of a person.

Classical depressive symptoms

• Depressed mood which includes persistent feeling of sadness or hopelessness.

•  Loss of interest in daily activities or reduced motivation.

•  Lack of energy or marked fatigue.

•  Difficulty concentrating, impaired cognition and focus.

Atypical symptoms

•  Increased appetite and weight gain: Craving for carbohydrates leading to overeating and increased weight.

•  Excessive sleepiness and prolonged duration of sleep.

Seasonal patterns

Winter type: Some people have symptoms which typically start in fall- winter and remit in spring-summer.

Summer type: Though less common, people with this pattern have symptoms which appear in spring-summer and remit in fall-winter.

The good news is that SAD is treatable.

Effective management of SAD involves a combination of light therapy, pharmacotherapy and lifestyle modifications.

•  Light therapy: It involves exposing the individual to the bright light that mimics natural sunlight, which can help relieve depressive symptoms. Bright light therapy (BLT) for SAD is used at an intensity of 10,000 lux for 30–90 minutes daily, usually within 1 hour of arising in the morning. Light therapy is well documented and effective treatment for winter SAD and clinical response to treatment is usually observed in first few weeks. Light basically activates a region in the brain called as suprachiasmatic nucleus, which is the circadian pacemaker of the brain. This mechanism positively affects the mood, sleep, circadian rhythms, and hypothalamic-pituitary-adrenal axis activity in patients with SAD.

•  Pharmacotherapy: Antidepressants such as the Selective Serotonin Reuptake Inhibitors (SSRIs) are also prescribed in some cases.

•  Cognitive behavioral therapy for SAD (CBT-SAD): It focuses on breaking the vicious cycles of negative emotions, physical sensations, cognitions, and behaviors by challenging maladaptive beliefs and developing healthier coping strategies. CBT is the most extensively researched and highly recommended therapy for depression.

•  Combination therapy: Combining antidepressants with light therapy or cognitive behavioural therapy can enhance treatment outcomes.

•  Life style modifications: Regular exercise, exposure to natural light, a balanced diet, good sleep hygiene, and relaxation techniques such as mindfulness and meditation may help alleviate symptoms of depression. However, if symptoms persist despite these interventions, it is important to seek professional help as early as possible.

A Closing Thought

If you recognize yourself in this post, you are not lazy, weak, or dramatic. Your brain and body may be responding to the season in a real way. And if you recognize that your loved one is pulling away as the fall or winter approaches, try replacing “why are you feeling this way?” with “I have noticed things feel heavier lately. How can I help”? Small acts of understanding and kindness can help someone reach support earlier. Seasons change, and so can how we move through them.

References:

American Psychiatric Association. (2024, March). Seasonal affective disorder (SAD). Psychiatry.org. https://www.psychiatry.org/Patients-Families/Seasonal-Affective-Disorder

Magnusson, A., & Boivin, D. (2003). Seasonal affective disorder: An overview. Chronobiology International, 20(2), 189–207. https://doi.org/10.1081/CBI-120019310

Melton, S., Wieland, S., Bastounis, A., & Carter, T. (2025). Cognitive behavioral therapy for seasonal affective disorder: A systematic review and meta-analysis. The Cognitive Behavior Therapist, 18, e41. https://doi.org/10.1017/S1754470X2510024X

Michael, M. R. (2020, December 9). Seasonal affective disorder (SAD) treatment & management: Approach considerations, bright light therapy, psychotherapy. Medscape. https://emedicine.medscape.com/article/2500054-treatment

Nature Index. (n.d.). Therapeutic approaches for seasonal affective disorder. Nature. https://www.nature.com/nature-index/topics/l4/therapeutic-approaches-for-seasonal-affective-disorder

Partonen, T. (2006). Pharmacotherapy for seasonal affective disorder. In Sleep and sleep disorders (pp. 121–126). Springer. https://doi.org/10.1007/0-387-27682-3_12

Rohan, K. J., Meyerhoff, J., Ho, S.-Y., Evans, M., Postolache, T. T., & Vacek, P. M. (2016). Outcomes one and two winters following cognitive-behavioural therapy or light therapy for seasonal affective disorder. American Journal of Psychiatry, 173(3), 244–251. https://doi.org/10.1176/appi.ajp.2015.15060773

Rosenthal, N. E., Sack, D. A., Gillin, J. C., Lewy, A. J., Goodwin, F. K., Davenport, Y., Mueller, P. S., Newsome, D. A., & Wehr, T. A. (1984). Seasonal affective disorder: A description of the syndrome and preliminary findings with light therapy. Archives of General Psychiatry, 41(1), 72–80. https://doi.org/10.1001/archpsyc.1984.01790120076010