Why Winter Makes People Feel SAD; About Seasonal Affective Depression, And How To Tackle It

Last Updated:November 07, 2025, 12:28 IST

SAD is a clinical form of depression that follows a seasonal pattern. Most people experience its onset in late autumn or early winter, with symptoms easing by early spring

Every year, as winter creeps in and daylight hours begin to shrink, millions of people around the world notice a shift within themselves that has nothing to do with temperature or weather forecasts. Mornings feel heavier, motivation dissolves, energy dips, and a persistent gloom settles in without an obvious reason. What begins as a simple “winter slump” can, for many, turn into something far more serious: Seasonal Affective Depression, better known as SAD.

While winter is culturally framed around celebration, holidays, and cozy evenings, the mental-health side of winter rarely receives the same attention. Yet, this seasonal mood disorder affects people globally, and India is no exception. Although comprehensive epidemiological data does not exist for India, psychological and psychiatric experts believe more than 10 million Indians are affected every winter, many without diagnosis or awareness. In the US, where mental-health tracking is more structured, about 5% of adults experience SAD every year.

As temperatures drop across India and the northern hemisphere, it becomes crucial to understand what SAD really is, what triggers it, who is most vulnerable, and how people can manage or prevent its symptoms before they spiral into full-blown depression.

Let’s understand the science, the symptoms, the cultural blind spots, and the strategies that can help people reclaim their winters.

What Exactly Is Seasonal Affective Depression?

SAD is a clinical form of depression that follows a seasonal pattern. Most people experience its onset in late autumn or early winter, with symptoms easing by early spring. A much smaller group experiences the opposite pattern — depressive symptoms emerging in summer — but winter SAD is overwhelmingly the most common.

SAD is not just “winter blues” or laziness. It is characterised by a recurrent, predictable onset of depression linked to seasonal changes, primarily triggered by reduced daylight exposure.

Researchers have studied SAD for decades, and while it is still not fully understood, most scientific theories focus on one central biological mechanism: our circadian rhythm.

Humans are naturally wired to follow a 24-hour cycle regulated by light. This internal body clock influences everything — sleep, appetite, hormone levels, body temperature, and emotional regulation. When winter arrives and daylight hours shrink, the brain receives less natural light stimulation. This shift can desynchronise internal rhythms from the natural day-night cycle.

When the brain loses sync with the environment, several chemical changes follow:

1. Melatonin Levels Increase

Melatonin is a hormone that induces sleepiness. In darker months, the brain produces more of it for longer periods, making people feel excessively fatigued, groggy, and low-energy.

2. Serotonin Levels Decrease

Serotonin is the “feel-good” neurotransmitter associated with mood stability and emotional well-being. Reduced sunlight decreases its production, leading to sadness, irritability, and emotional numbness.

3. Vitamin D Levels Drop

Sunlight triggers vitamin D production in the body, which has a known connection to mood regulation. Low vitamin D levels are widely linked to depressive symptoms.

Together, these changes create a biological environment where depressive symptoms flourish for certain people — explaining why SAD isn’t simply psychological but a neurochemical response to seasonal disruption.

How Common Is SAD Globally And In India?

Global research shows wide variations depending on geography. Countries located far from the equator record significantly higher cases of SAD, especially northern European countries where winter days are extremely short.

United States: About 5% of adults suffer from SAD annually, with women four times more likely than men to experience symptoms.

Canada & Nordic Countries: Prevalence rates can reach 8–10% or higher because daylight hours in winter drastically reduce.

India: There is no official nationwide number, but mental-health professionals and small-scale studies suggest more than 10 million people are affected each winter.

Why Does SAD Exist In India If Daylight Variation Is Less Extreme?

Experts believe the rise of urban lifestyles — long hours indoors, limited sunlight exposure, late-night schedules, and pollution blocking natural light — plays a major role. Northern states, which experience more dramatic winter shifts, report higher cases through local clinical data.

Ironically, modern living has made Indians more vulnerable to SAD than earlier generations, not because winters are harsher, but because indoor, screen-heavy lifestyles have pushed natural light exposure to historic lows.

What Do People With SAD Actually Feel?

The symptoms are often subtle at first and then intensify gradually. Many people mistake SAD for tiredness, stress, or burnout. What makes it distinct from regular mood dips is its predictable pattern and its impact on daily functioning.

Most people with SAD experience:

A Persistent Drop In Mood: Individuals often describe a “heavy sadness” that feels disproportionate and inexplicable. Joy feels muted, and activities that once brought pleasure no longer feel meaningful.

Low Energy & Excessive Sleepiness: Because winter alters melatonin production, people tend to oversleep yet still feel fatigued. Morning lethargy and afternoon energy crashes become routine.

Increased Appetite & Weight Gain: A unique feature of winter SAD is craving carbohydrates and sugary foods. This is the body’s way of compensating for the drop in serotonin levels, since carbs can produce temporary mood elevation.

Difficulty Concentrating: Brain fog is common. People may struggle with decision-making, focus, memory, or completing tasks that normally feel manageable.

Social Withdrawal: People with SAD often become quieter, less responsive, and avoid social interactions. This tends to be misinterpreted as irritability or laziness.

Heightened Anxiety: While depression dominates, many people also experience restlessness, worry, or a sense of dread.

Loss Of Motivation: Work, exercise, hobbies, and even routine activities like cooking or cleaning begin to feel overwhelming.

SAD symptoms are not uniform; they range from mild to debilitating. In severe cases, SAD can lead to major depressive episodes.

Who Is Most At Risk?

Though SAD can affect anyone, researchers have identified several patterns.

Women Are More Affected: Women are nearly four times more likely than men to develop SAD, possibly due to hormonal and neurochemical differences.

People Living In Northern Or Low-Sunlight Regions: Even in India, residents in the northern belt experience stronger seasonal shifts, making SAD more common in cities like Delhi, Chandigarh, Srinagar and Shimla.

Young Adults Are More Vulnerable: SAD often starts between ages 18 and 30, though children and teenagers can also experience it.

People With A History Of Mood Disorders: Individuals with previous depression or bipolar disorder have a higher risk of developing seasonal depressive episodes.

People With Indoor Or Night-Shifting Jobs: Those who work indoors, especially in offices without sunlight exposure, or those who work night shifts face greater disruption of circadian rhythms.

Why Are More Indians Reporting SAD Now?

While SAD is not new, awareness around it is. Several factors are contributing to its rise, or at least to its increased recognition.

Urban Lifestyles Reduce Sun Exposure

Skyscrapers, offices without windows, longer commutes, and pollution drastically limit natural light. Even in bright Indian cities, actual sun exposure is now minimal.

Screen Time Has Replaced Daylight

LED light from screens, especially at night, disrupts melatonin and circadian rhythms. The body can no longer rely on natural cues to regulate mood and sleep.

Post-Pandemic Mental-Health Awareness

People today are more willing to acknowledge symptoms, seek help, and talk about mental health compared to previous generations.

Climate Variability

Smog-filled winters in Delhi or northern states create darker environments than normal, reducing sunlight further.

How Is SAD Diagnosed?

There is no single test for SAD. Psychiatrists or clinical psychologists rely on:

• Impact on daily functioning

SAD is officially classified as a subtype of Major Depressive Disorder (MDD) with a seasonal pattern.

Many people never seek a formal diagnosis, assuming winter sadness is “normal.” But any depression lasting more than two weeks deserves clinical evaluation.

How Can SAD Be Treated Or Managed?

Since SAD is deeply linked to light exposure, treatment focuses on resetting the circadian rhythm and stabilizing mood chemistry.

Light Therapy (Phototherapy)

In countries like the US, Canada and the UK, light therapy is the most common treatment. Patients sit in front of a bright white-light box for 20-40 minutes each morning. These lamps simulate natural daylight and help regulate melatonin and serotonin production. In India, light-therapy devices are slowly entering the market, but awareness remains low.

Daily Sun Exposure

Even 15-30 minutes of early-morning sunlight can significantly improve symptoms. A walk between 7 am and 9 am is considered ideal as natural light then is strong enough to reset circadian rhythms.

Exercise

Physical activity raises serotonin and dopamine levels. Yoga, brisk walking, dancing, or any enjoyable movement helps counteract emotional heaviness.

Vitamin D

Doctors often check vitamin D levels because winter deficiency is rampant in India. Correcting the deficiency can ease SAD symptoms.

Cognitive Behavioural Therapy (CBT)

CBT helps individuals challenge negative thought patterns and overcome motivational loss. It is especially helpful when combined with light therapy.

Dietary Adjustments

Consuming complex carbohydrates, fresh vegetables, lean proteins, and omega-3 rich foods can help regulate mood and energy.

Sleep Hygiene

Setting fixed sleep-wake timings, reducing screen exposure before bed, and ensuring a dark, cool room help stabilise melatonin production.

Medication

For moderate to severe SAD, psychiatrists may prescribe antidepressants. These are clinically effective but require supervision.

Why SAD Needs Attention, Not Normalisation

In India, winter depression is still trivialised as laziness, moodiness, oversleeping, or lack of discipline.

But SAD is a genuine medical condition that affects productivity, relationships, immunity, physical health, and long-term mental well-being.

Unchecked SAD can worsen into severe depression or trigger complications in people prone to mood disorders.

With climate instability, rising pollution, and indoor lifestyles, SAD is expected to increase in the country, making awareness and early intervention more important than ever.

Winter Is Not Really The Problem

Seasonal Affective Depression does not mean people are allergic to winter or incapable of enjoying the season. Instead, it reflects how deeply human biology depends on sunlight and rhythm. When daylight changes, so do human beings.

Understanding SAD means recognising that mental health is not just shaped by emotions or external pressures, but also by the environment bodies evolved to live in.

As winter sets in, the best defence is awareness. Knowing what SAD looks like, why it happens, and how to manage it can make the difference between a dark season and a healthy one.

Shilpy Bisht

Shilpy Bisht, Deputy News Editor at News18, writes and edits national, world and business stories. She started off as a print journalist, and then transitioned to online, in her 12 years of experience. Her prev…Read More

Shilpy Bisht, Deputy News Editor at News18, writes and edits national, world and business stories. She started off as a print journalist, and then transitioned to online, in her 12 years of experience. Her prev… Read More

While winter is culturally framed around celebration, holidays, and cozy evenings, the mental-health side of winter rarely receives the same attention. Yet, this seasonal mood disorder affects people globally, and India is no exception. Although comprehensive epidemiological data does not exist for India, psychological and psychiatric experts believe more than 10 million Indians are affected every winter, many without diagnosis or awareness. In the US, where mental-health tracking is more structured, about 5% of adults experience SAD every year.

As temperatures drop across India and the northern hemisphere, it becomes crucial to understand what SAD really is, what triggers it, who is most vulnerable, and how people can manage or prevent its symptoms before they spiral into full-blown depression.

Let’s understand the science, the symptoms, the cultural blind spots, and the strategies that can help people reclaim their winters.

What Exactly Is Seasonal Affective Depression?

SAD is a clinical form of depression that follows a seasonal pattern. Most people experience its onset in late autumn or early winter, with symptoms easing by early spring. A much smaller group experiences the opposite pattern — depressive symptoms emerging in summer — but winter SAD is overwhelmingly the most common.

SAD is not just “winter blues” or laziness. It is characterised by a recurrent, predictable onset of depression linked to seasonal changes, primarily triggered by reduced daylight exposure.

Researchers have studied SAD for decades, and while it is still not fully understood, most scientific theories focus on one central biological mechanism: our circadian rhythm.

Humans are naturally wired to follow a 24-hour cycle regulated by light. This internal body clock influences everything — sleep, appetite, hormone levels, body temperature, and emotional regulation. When winter arrives and daylight hours shrink, the brain receives less natural light stimulation. This shift can desynchronise internal rhythms from the natural day-night cycle.

When the brain loses sync with the environment, several chemical changes follow:

1. Melatonin Levels Increase

Melatonin is a hormone that induces sleepiness. In darker months, the brain produces more of it for longer periods, making people feel excessively fatigued, groggy, and low-energy.

2. Serotonin Levels Decrease

Serotonin is the “feel-good” neurotransmitter associated with mood stability and emotional well-being. Reduced sunlight decreases its production, leading to sadness, irritability, and emotional numbness.

3. Vitamin D Levels Drop

Sunlight triggers vitamin D production in the body, which has a known connection to mood regulation. Low vitamin D levels are widely linked to depressive symptoms.

Together, these changes create a biological environment where depressive symptoms flourish for certain people — explaining why SAD isn’t simply psychological but a neurochemical response to seasonal disruption.

How Common Is SAD Globally And In India?

Global research shows wide variations depending on geography. Countries located far from the equator record significantly higher cases of SAD, especially northern European countries where winter days are extremely short.

United States: About 5% of adults suffer from SAD annually, with women four times more likely than men to experience symptoms.

Canada & Nordic Countries: Prevalence rates can reach 8–10% or higher because daylight hours in winter drastically reduce.

India: There is no official nationwide number, but mental-health professionals and small-scale studies suggest more than 10 million people are affected each winter.

Why Does SAD Exist In India If Daylight Variation Is Less Extreme?

Experts believe the rise of urban lifestyles — long hours indoors, limited sunlight exposure, late-night schedules, and pollution blocking natural light — plays a major role. Northern states, which experience more dramatic winter shifts, report higher cases through local clinical data.

Ironically, modern living has made Indians more vulnerable to SAD than earlier generations, not because winters are harsher, but because indoor, screen-heavy lifestyles have pushed natural light exposure to historic lows.

What Do People With SAD Actually Feel?

The symptoms are often subtle at first and then intensify gradually. Many people mistake SAD for tiredness, stress, or burnout. What makes it distinct from regular mood dips is its predictable pattern and its impact on daily functioning.

Most people with SAD experience:

A Persistent Drop In Mood: Individuals often describe a “heavy sadness” that feels disproportionate and inexplicable. Joy feels muted, and activities that once brought pleasure no longer feel meaningful.

Low Energy & Excessive Sleepiness: Because winter alters melatonin production, people tend to oversleep yet still feel fatigued. Morning lethargy and afternoon energy crashes become routine.

Increased Appetite & Weight Gain: A unique feature of winter SAD is craving carbohydrates and sugary foods. This is the body’s way of compensating for the drop in serotonin levels, since carbs can produce temporary mood elevation.

Difficulty Concentrating: Brain fog is common. People may struggle with decision-making, focus, memory, or completing tasks that normally feel manageable.

Social Withdrawal: People with SAD often become quieter, less responsive, and avoid social interactions. This tends to be misinterpreted as irritability or laziness.

Heightened Anxiety: While depression dominates, many people also experience restlessness, worry, or a sense of dread.

Loss Of Motivation: Work, exercise, hobbies, and even routine activities like cooking or cleaning begin to feel overwhelming.

SAD symptoms are not uniform; they range from mild to debilitating. In severe cases, SAD can lead to major depressive episodes.

Who Is Most At Risk?

Though SAD can affect anyone, researchers have identified several patterns.

Women Are More Affected: Women are nearly four times more likely than men to develop SAD, possibly due to hormonal and neurochemical differences.

People Living In Northern Or Low-Sunlight Regions: Even in India, residents in the northern belt experience stronger seasonal shifts, making SAD more common in cities like Delhi, Chandigarh, Srinagar and Shimla.

Young Adults Are More Vulnerable: SAD often starts between ages 18 and 30, though children and teenagers can also experience it.

People With A History Of Mood Disorders: Individuals with previous depression or bipolar disorder have a higher risk of developing seasonal depressive episodes.

People With Indoor Or Night-Shifting Jobs: Those who work indoors, especially in offices without sunlight exposure, or those who work night shifts face greater disruption of circadian rhythms.

Why Are More Indians Reporting SAD Now?

While SAD is not new, awareness around it is. Several factors are contributing to its rise, or at least to its increased recognition.

Urban Lifestyles Reduce Sun Exposure

Skyscrapers, offices without windows, longer commutes, and pollution drastically limit natural light. Even in bright Indian cities, actual sun exposure is now minimal.

Screen Time Has Replaced Daylight

LED light from screens, especially at night, disrupts melatonin and circadian rhythms. The body can no longer rely on natural cues to regulate mood and sleep.

Post-Pandemic Mental-Health Awareness

People today are more willing to acknowledge symptoms, seek help, and talk about mental health compared to previous generations.

Climate Variability

Smog-filled winters in Delhi or northern states create darker environments than normal, reducing sunlight further.

How Is SAD Diagnosed?

There is no single test for SAD. Psychiatrists or clinical psychologists rely on:

• Impact on daily functioning

SAD is officially classified as a subtype of Major Depressive Disorder (MDD) with a seasonal pattern.

Many people never seek a formal diagnosis, assuming winter sadness is “normal.” But any depression lasting more than two weeks deserves clinical evaluation.

How Can SAD Be Treated Or Managed?

Since SAD is deeply linked to light exposure, treatment focuses on resetting the circadian rhythm and stabilizing mood chemistry.

Light Therapy (Phototherapy)

In countries like the US, Canada and the UK, light therapy is the most common treatment. Patients sit in front of a bright white-light box for 20-40 minutes each morning. These lamps simulate natural daylight and help regulate melatonin and serotonin production. In India, light-therapy devices are slowly entering the market, but awareness remains low.

Daily Sun Exposure

Even 15-30 minutes of early-morning sunlight can significantly improve symptoms. A walk between 7 am and 9 am is considered ideal as natural light then is strong enough to reset circadian rhythms.

Exercise

Physical activity raises serotonin and dopamine levels. Yoga, brisk walking, dancing, or any enjoyable movement helps counteract emotional heaviness.

Vitamin D

Doctors often check vitamin D levels because winter deficiency is rampant in India. Correcting the deficiency can ease SAD symptoms.

Cognitive Behavioural Therapy (CBT)

CBT helps individuals challenge negative thought patterns and overcome motivational loss. It is especially helpful when combined with light therapy.

Dietary Adjustments

Consuming complex carbohydrates, fresh vegetables, lean proteins, and omega-3 rich foods can help regulate mood and energy.

Sleep Hygiene

Setting fixed sleep-wake timings, reducing screen exposure before bed, and ensuring a dark, cool room help stabilise melatonin production.

Medication

For moderate to severe SAD, psychiatrists may prescribe antidepressants. These are clinically effective but require supervision.

Why SAD Needs Attention, Not Normalisation

In India, winter depression is still trivialised as laziness, moodiness, oversleeping, or lack of discipline.

But SAD is a genuine medical condition that affects productivity, relationships, immunity, physical health, and long-term mental well-being.

Unchecked SAD can worsen into severe depression or trigger complications in people prone to mood disorders.

With climate instability, rising pollution, and indoor lifestyles, SAD is expected to increase in the country, making awareness and early intervention more important than ever.

Winter Is Not Really The Problem

Seasonal Affective Depression does not mean people are allergic to winter or incapable of enjoying the season. Instead, it reflects how deeply human biology depends on sunlight and rhythm. When daylight changes, so do human beings.

Understanding SAD means recognising that mental health is not just shaped by emotions or external pressures, but also by the environment bodies evolved to live in.

As winter sets in, the best defence is awareness. Knowing what SAD looks like, why it happens, and how to manage it can make the difference between a dark season and a healthy one.

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