DoctorSpeak: Why do you feel SAD in winter

Priya (32), a Delhi-based marketing professional, has been having recurrent winter depression since her late 20s. From October-November to February every year, she experiences profound fatigue, hypersomnia (10-12 hours’ sleep yet exhausted), 5-7 kg weight gain because of intense carbohydrate cravings, persistent low mood, anhedonia (diminished capacity to experience pleasure), poor concentration and feelings of hopelessness. These symptoms disappear completely by April-May. She has been diagnosed with Seasonal Affective Disorder (SAD). A family history of depression and reduced winter sunlight are key triggers.

I have another patient, Raj (45), a Delhi government employee, who, too, has been suffering from recurrent winter depression since the past over 10 years. Every year, December onwards, he experiences marked irritability, extreme lethargy, hypersomnia (10-12 hours sleep yet exhausted), carb-cravings and weight gain, severe social withdrawal, hopelessness, and suicidal thoughts. Symptoms continue till February-March, and disappear by spring with no reoccurrence till winters arrive again.

His diagnosis is similar to Priya’s — SAD or major depressive disorder recurrent with seasonal pattern (winter type). A family history of bipolar disorder and Delhi’s foggy winters sans sunlight are the major reasons.

Psychiatry OPDs across India are full of patients who often feel low as winters begin and intensify. SAD is a type of depression or mood disorder that recurs every year during the same season (most often in autumn or winter) and improves or completely goes away in another season (usually spring or summer). Symptoms include a persistent low mood, feeling tired all the time, no interest in daily activities, and some more symptoms similar to those of depression.

A review in StatPearls explains that SAD often includes special symptoms called ‘atypical features’ — sleeping too much, eating a lot (especially sweets and carbohydrates), gaining weight, and feeling very tired — along with usual signs of depression like sadness, no energy and trouble in concentrating.

Globally, SAD affects nearly 10 per cent of the total population, with higher rates in places far from the equator where winter darkness is more extreme.

In India, SAD is generally less common because of its closeness to equator. However, in northern states like Delhi, Punjab, and Kashmir, thick winter fog, pollution, cold weather, and people staying indoors that reduces their exposure to natural sunlight, can trigger symptoms of SAD. Studies from North India report SAD in at least 18 per cent of the patients who are already suffering from other mood disorders like depression or bipolar.

Other studies say millions of Indians may experience SAD-like symptoms during winter months. Doctors in Delhi often see two to four new SAD cases daily during peak winter months (November-February). Women, young adults (20s-30s), and people with a family history of mood disorders are at a higher risk.

Why does it happen

The main cause is reduced sunlight during autumn and winter months. Decreased amount of sunlight disturbs the body’s internal clock/circadian rhythm, which affects sleep, energy levels and mood.

Key factors & mechanisms:

Circadian rhythm problems: Shorter days cause increased production of melatonin (sleep hormone) and a shift/misalignment in the body’s daily internal clock.

Brain chemical changes: Low levels of serotonin (a mood-regulating chemical), plus disruption in other neurotransmitters like dopamine, norepinephrine, and glutamate.

Reduced response to light: Some people’s eyes (retina) are less sensitive to light, so they get less mood-boosting effect from whatever sunlight is available.

Genetic factors: Family history plays a key role; certain gene variations linked to serotonin, dopamine, and the body’s clock increase risk, say some studies.

Other factors: Low vitamin D levels from less sun exposure, and psychological factors like negative thoughts about winter can make symptoms worse.

In most cases of SAD, all these factors work together, that’s why not everyone in low-light areas gets affected with SAD. The disorder usually starts when biological vulnerability meets the environmental trigger of shorter, darker days.

Treatment options

Treatment, such as in Priya’s case, includes morning bright light therapy, combined with Cognitive Behavioural Therapy to address negative seasonal thoughts. As a preventive measure, most patients of SAD are advised to take a low-dose antidepressant as well as vitamin D supplements before winter’s onset. Lifestyle changes include exposure to morning sunlight, regular exercise, and a regular sleep routine. Priya’s symptoms improved significantly within weeks after these changes. Raj’s treatment plan was also on similar lines.

Experts emphasise that an integrative approach, combining light therapy, psychotherapy, medication (when needed), and lifestyle adjustments, gives the best and longest-lasting results. If you experience seasonal low mood persistently, consult an expert as timely help can make a big difference.

— The writer is Clinical Psychologist, Mind Healing Clinic, New Delhi

Simple steps to deal with SAD disorder

Most SAD patients get better with simple lifestyle changes and some professional help.

— Step outside for exposure to morning sunlight every day.

— Have a daily exercise routine like walking, yoga, stretching, etc.

— A healthy diet is a key factor to keep a steady mood. Apart from whole grains, seasonal fruits, vegetables, pulses, legumes, include natural sources of vitamin D such as fatty fish, egg yolks, fortified foods, including cereals and juices, dairy, (cheese, yoghurt), plant milks, mushrooms, etc. Take vitamin D supplements if your levels are low.

— Keep a regular sleeping schedule.

— Indulge in group activities with family and friends.

Factcheck: Over 10 million Indian experience SAD symptoms. Unlike West, Indian studies, especially from North India, find a significant trend for summer depression, with peaks in winter and smaller peaks in summer, sometimes including seasonal mania, says a study in the Journal of Affective Disorders. SAD prevalence is linked to latitude, but studies in India show varied rates, with some from Kashmir finding high seasonal depression (late winter/early spring), while others in North India note summer patterns, according to the Indian Journal of Social Psychiatry. SAD is less understood in India, partly because seasonal daylight changes are less pronounced. Also Indians often lack the classic 'atypical' features (like weight/sleep gain) seen in temperate climates.