Seasonal affective disorder: everything there is to know!

Published 29 Jan 2023 • By Claudia Lima

SAD is most often associated with winter, which is why it is also called winter depression. But it is also known as seasonal affective disorder (SAD). There are two types of this condition: winter SAD and the much less common summer SAD.
It has recently been recognised as a condition in its own right.

So what exactly is SAD? What are its symptoms? How can it be treated?

Find all the answers in our article!

Seasonal affective disorder: everything there is to know!

What is seasonal affective disorder? 

According to the DSM V, the 5th and the latest version of the Diagnostic and Statistical Manual of Mental Disorders, SAD is defined as a depressive episode with a seasonal character. This means that there is a regular temporal relationship between the occurrence of depressive episodes and a particular time of the year.

Nevertheless, according to the ICD-10, the International Classification of Mental Disorders, revised for the 10th time, SAD is one of the recurrent depressive conditions and disorders.

1 in 10 people are suffering with this disorder, mostly people working indoors and/or living in regions with little sunshine. SAD tends to affect people who are very sensitive to light. Women are usually more affected than men.

SAD is a major depressive condition related to the changing of seasons and more specifically to the lack of natural light. To qualify as a SAD, it must occur annually and for at least two consecutive years.

What are the symptoms of SAD and what causes it? 

Seasonal depression, especially winter depression, should not be confused with winter blues. The latter is also temporary but the symptoms are much milder. The most common symptoms of SAD are:

  • Loss of energy, chronic fatigue,
  • Lack of concentration, periods of sleepiness,
  • Sadness, a feeling of loneliness, and/or desire to isolate oneself,
  • Mood disorders (irritability),
  • Stress, anxiety,
  • Decreased libido,
  • Sleep disturbances,
  • Loss of interest in habitual activities,
  • Decreased productivity,
  • Cravings for sugary and high-calorie foods, weight gain,
  • Dark or suicidal thoughts.

SAD is thought to be a direct consequence of hormonal changes induced by the decrease in light. The production of certain types of hormones - melatonin and serotonin - is disturbed. This has an impact on sleep, mood and the internal biological clock, which can lead to the development of depressive symptoms.

is a hormone produced in our brain. Its main function is to provide our body with time cues, which is why it is essential for the circadian regulation of our sleep. It is activated by the impact of light on the retina of the eye. The more of it we produce, the more we want to sleep. Serotonin is linked to the regulation of mood and sleep. The lack of serotonin makes one more irritable.

How is SAD treated? How to avoid it? 

It is the psychiatrist who makes the diagnosis of SAD. A general practitioner, if not informed, will not notice the subtlety of the seasonal character and will diagnose a classic depression. It is also important for the psychiatrist to check whether this depression is not part of a bipolar disorder.

In order to treat winter SAD, light therapy is recommended as a first step.

And if the symptoms have a significant impact on the patient's daily life, a prescription of antidepressants and psychotherapy may be necessary.

Other alternative methods exist such as homeopathy, phytotherapy, aromatherapy and naturopathy, among others.

Here are some useful tips for treating and preventing SAD:

  • Take daily walks in the morning to catch as much daylight as possible or plan light therapy sessions,
  • Let as much light as possible into your living space, opt for light colours and few decorations,
  • Eat a healthy and balanced diet and fill up on tryptophan, an amino acid that enables the synthesis of serotonin, which is transformed into melatonin, (e.g. cod, salami, parmesan, parsley, pumpkin seeds, soya, milk and cheese), omega-3 and magnesium
  • Practise sports, if possible outdoors,
  • Use St. John's wort, the benefits of have been proven scientifically and are recongnised by the WHO,
  • Practice mindfulness or meditation, to free yourself from negative thoughts,
  • Go out, eat out, meet friends and enjoy the moment.

Summer SAD occurs with the arrival of spring, and patients feel oppressed by the arrival of warmer weather. Its symptoms are similar to those of the winter SAD except that patients with summer depression lose appetite and weight and become restless. The longer daylight hours and the heat disturb their sleep. The idea of dressing more lightly can cause anxiety, especially in people with physical complexes. No specific treatment has been devised other than recommendations to spend a few extra hours in the dark, take cool showers and use air conditioning.

To sum it all up, SAD can be rather difficult to manage, but there are effective ways to combat it. Take care of yourself, schedule time just for yourself and don't hesitate to talk to someone if you feel the need.

Was this article helpful to you?
Give it a like and share your thoughts and questions with the community in the comments below!
Take care!
avatar Claudia Lima

Author: Claudia Lima, Health Writer

Claudia is a content creator at Carenity, specializing in health writing.

Claudia holds a master's degree in Entrepreneurship and an Executive MBA in Sales and Marketing Management. She is specialized in... >> Learn more


You will also like

Anti-depressants: Major study finds they work


Anti-depressants: Major study finds they work

Read the article
People with depression are 60% more likely to develop diabetes


People with depression are 60% more likely to develop diabetes

Read the article
Depression diagnosis: Carenity members tell their story

Postpartum depression

Depression diagnosis: Carenity members tell their story

Read the article
Alcoholism and depression: one family fights the stigma


Alcoholism and depression: one family fights the stigma

See the testimonial

Most commented discussions

Fact sheets