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January: Emotional Health


Seasonal Affective Disorder and Phototherapy

The “winter blues” are real for many of us in the fall and winter months. As our exposure to daylight decreases, we often have lower moods, gain weight or sleep more – but we still function in a healthy manner. Conversely, at this time of year, some of us go into a full clinical depression that’s called seasonal affective disorder (SAD).

As the days get shorter and the weather gets colder, SAD typically impacts us at these rates:

  • About two or three out of every 100 people experience it
  • It’s more common in women than in men
  • It usually begins in your twenties
  • Older people have a lower risk
  • Children rarely experience it

Factors Linked to SAD

The exact cause of SAD is unknown, but the medical community agrees that it’s related to several factors:

  • Seasonal light variations – the body’s internal clock, which controls your temperature and hormone production, can be “thrown off” with reduced exposure to sunlight
  • Melatonin levels – the pineal gland in the brain, which controls your daily rhythms and moods, is under-stimulated by low amounts of sunlight entering your eyes
  • Vitamin D levels – if you have a vitamin D deficiency, it makes you more vulnerable to many mood disorders; see our Vitamin D and Mood Disorders tip sheet (PDF) for details
  • Northern climate – the shorter days and colder weather in northern communities makes it very difficult for you to get enough exposure to sunlight

Symptoms and Complications

SAD can be difficult to diagnose because many of its symptoms are similar to those for other types of depression.

You’re likely suffering from SAD if, with no other explanation for mood or behaviour changes, you have any of these symptoms for at least two consecutive winters:

  • Increased appetite with weight gain – crave sweet or starchy foods
  • Increased sleep and daytime sleepiness
  • Less energy and ability to concentrate in the afternoon
  • Loss of interest in work or other activities
  • Slow, sluggish, lethargic movement
  • Social withdrawal
  • Unhappiness and irritability
  • For children – symptoms include irritability, problems in school and difficulty getting out of bed

Make an appointment with your doctor to learn if you have SAD. Your doctor will ask you questions about your symptoms and perform a physical exam, and possibly order blood tests to rule out medical conditions that have similar symptoms, like thyroid issues.

Treating SAD with Phototherapy

Phototherapy, where you’re exposed to full-spectrum white light, can often eliminate SAD symptoms quickly. You should always consult your doctor, and get your eyes checked by an optometrist, before starting phototherapy, as it’s not for everyone.

Phototherapy is delivered in a phototherapy device ("light box") that you can purchase or rent from a private supplier or medical supply store. It uses a special lamp with a very bright fluorescent light (10,000 lux) that mimics sunlight.

For safe phototherapy sessions, follow your doctor's instructions and these guidelines:

  • You can read in the light box – but never sleep in it
  • Sit a couple of feet away from the light box for about 30 minutes every day
  • Do your sessions in the early morning to mimic sunrise
  • Keep your eyes open – but don’t look straight into the bright lamp

Your SAD symptoms should be greatly reduced over three to four weeks with phototherapy. They may reappear, however, if you completely stop your sessions.

Besides phototherapy, your full SAD-treatment program should also include exercise and good nutrition, as well as antidepressants in severe cases.

Check out these other treatments for seasonal affective disorder (PDF).

Side-effects of Phototherapy

While phototherapy will often eliminate your SAD symptoms quickly, it can give you these side-effects:

  • Eye strain
  • Headache
  • Mania

You should avoid phototherapy if you take drugs that make you more sensitive to light, such as psoriasis drugs, antibiotics or antipsychotics.

Preventing SAD

If you’ve suffered from SAD for at least two consecutive winters, you should talk to a mental healthcare professional about your prevention options. Starting a treatment program during the fall or early winter can prevent your symptoms from reappearing once winter really begins.


Sources:

Apple-a-Day

Canadian Mental Health Association

PubMed Health

University of Toronto