Understanding Seasonal Affective Disorder” is a short video from Toronto’s prestigious Centre for Addiction and Mental Health (CAMH) treatment and research hospital. Dr. Robert Levitan, Research Head in CAMH’s Mood and Anxiety Disorders Program, discusses the disorder and its treatments.

As days grow shorter in late fall and early winter, the lack of sunlight leads to changes in the circadian system that can trigger SAD. More common in women than men (up to 80% of sufferers are female), symptoms range in severity from the milder “winter blues” to severe depression with low energy, increased appetite and sleep, and psychological symptoms that include hopelessness and lethargy.

SAD is treatable, with methods ranging from cognitive behavioural therapy (CBT) to tryptophan to prescription antidepressants, but perhaps the most commonsense is light therapy. Special lamps are used with exposure to precise amounts of light each day, to make up for a lack of outdoor sun.

It’s important to use a special SAD lamp and not a random artificial light source, as the precise amount of light and type of wavelength is critical. A non-SAD lamp could damage eyesight from too much UV light, exposure to excess light at the wrong time of day can trigger mania in people with bipolar disorder, and not enough light will obviously not have a therapeutic effect on SAD symptoms. SAD lights are commonly sold in drug stores now, but please consult a mental health professional and follow instructions carefully before use. As Dr. Levitan notes, it’s important to have the disorder professionally diagnosed before starting a treatment.

Read more about SAD and its treatments.