Why does winter make me SAD?

With gray skies and cold weather, winter leaves a lot of us feeling down. This year we’re also coping with the stress of COVID-19. With this difficult combination, it’s important to take extra care of our mental health this season. 

Those winter blahs — eating more, sleeping more, and having less energy — are something lots of us experience. For some people, seasonal mood changes turn into more serious depression called seasonal affective disorder (SAD). Here’s what you need to know about SAD, and how you can ease the symptoms of winter blues.

Symptoms of seasonal affective disorder

SAD is a clinical depression brought on by the change of season. It usually begins during the fall months, when the days start getting noticeably shorter. As winter approaches symptoms become more severe. They include:

  • A loss of interest in activities you used to enjoy.
  • Feeling sad for most of the day, almost every day.
  • Tiredness during the day.
  • Trouble getting a good night’s sleep.
  • Weight gain.
  • Food cravings, usually for foods that are sugary or starchy.
  • Feeling irritable.
  • Feeling hopeless or guilty.
  • No longer enjoying the company of friends and family.

It’s rare, but some people experience SAD in the summer months. In those cases, feelings of sadness usually come in the springtime and get stronger as the summer months approach.

What causes seasonal affective disorder?

Medical professionals still haven’t discovered exactly why people get SAD, but we do have some idea of how it affects the body. There are two chemicals that are imbalanced in people who get SAD in the wintertime — serotonin and melatonin. The third component to SAD is a disruption to your circadian rhythm.


Serotonin is a chemical your brain produces called a neurotransmitter. It’s responsible for:

  • Motor function
  • Reducing anxiety and depression
  • Stabilizing mood
  • Regulating appetite and sleep cycles
  • Increased focus

Serotonin levels are affected by exposure to sunlight. In wintertime, the short days and lack of sun cause a drop in serotonin production. This contributes to emotional disturbances like sadness and irritability.


Melatonin is a hormone that your brain produces. It’s created in response to darkness, and it helps regulate your sleep-wake cycle. When your melatonin levels are healthy, you wake up and fall asleep at appropriate hours without any trouble. With SAD, melatonin is released at the wrong time because it’s dark outside more often. This can leave you feeling tired and prone to sleeping at inconvenient times.

Circadian Rhythm

When your sleep-wake cycle is disrupted, over time it affects your circadian rhythm. The circadian rhythm is your internal clock. It tells your body when it should be tired and when it should wake up. Sunlight is one of the ways your circadian rhythm stays on track. Especially in the morning, light helps your internal clock understand it’s daytime. Low light in the wintertime can confuse your circadian rhythm. Without cues from natural light, you’re at risk of oversleeping.

Who is at risk for seasonal affective disorder?

Around 3% of Canadian adults experience SAD once in their lives. This isn’t mild seasonal sadness — it’s depression that disrupts daily life. About 15% of Canadians will have a lighter version of SAD that’s manageable enough to live life normally. 

Women are more likely to develop SAD than men. Luckily, as you get older, your risk of SAD decreases. Other risk factors include living in places that are far from the equator, and a family history of depression or SAD.

Ways to cope with seasonal affective disorder

Your doctor can help you narrow down the best treatment for you if you have SAD. Here are some common options.

Light therapy 

Sitting next to a bright lamp built specifically for SAD relief can help correct chemical imbalances. SAD lamps are used at home, usually for about 30 minutes each day. Although it’s possible to purchase a lamp without a prescription, checking in with your doctor first may help you avoid side effects like headaches and nausea. 


Many people who experience depression use medication to help them feel their best. Sometimes people with SAD start taking medication in late summer to get ahead of the changes in mood brought on by winter months. 


Getting regular support during the winter months can help you manage symptoms like negative thoughts. Counselling is a great way to put your seasonal depression into perspective. 

Lifestyle adjustments 

There are things you can work into your routines that relieve symptoms of depression. Physical activity releases chemicals like endorphins that improve your mood. Eating a diet low in sugar helps regulate your hormones, which also keep your emotions level. Experiment with healthy lifestyle practices a few times a week.

Seasonal affective disorder and COVID-19

We’ve all spent a lot more time indoors than usual this year. Especially if you have SAD, getting out into the daylight will help with winter blues. Even though we need to be socially distanced, it doesn’t mean we have to stay inside. Try a winter hike with your pet, or a socially distanced walk with friends or family. Exercise, daylight, and social connection will boost your mood. 

Seasonal affective disorder makes it tough to be your best self. Lack of light can leave you feeling sluggish and even depressed. If you’re feeling low, don’t ignore it. With the right combination of supports, you can make the most of a challenging season.

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