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Light therapy an effective treatment for non-seasonal depression

November 18, 2015

Light therapy is an effective treatment for people with non-seasonal depression, a new finding that Sunnybrook Health Science Centre researchers believe may change the way depression is treated.

“In our study, patients with non-seasonal depression who were treated with a combination of light therapy and an antidepressant saw significant improvement in their symptoms, while those who received only one of the treatments did not see the same level of improvement,” says study co-author Dr. Anthony Levitt, staff psychiatrist and chief, Sunnybrook's Hurvitz Brain Sciences Program.

The randomized, double-blind trial examined four combinations of treatment for non-seasonal major depressive disorder (MDD): light therapy and an antidepressant; light therapy and a placebo pill; a placebo light therapy box and an antidepressant; and a placebo light therapy box and a placebo pill.

In the trial, light therapy involved direct exposure to a fluorescent light box for 30 minutes each day for the duration of the trial, which lasted eight weeks. Light therapy has long been used as a treatment for seasonal affective disorder (SAD), but the effects of using it in patients with non-seasonal depression were not well-known.

Dr. Levitt and the researchers were surprised by just how effective the combination treatment of light therapy and an antidepressant proved to be.

“Adding light therapy had a positive effect on the largest number of patients in the study, and their depressive symptoms were reduced much more quickly. Light therapy is a low-cost treatment option with few side effects, and our findings show it could benefit many patients with MDD,” says Dr. Levitt, who is also professor, department of psychiatry at the University of Toronto.

According to the researchers, medications are effective for treating depression but only work in about 60 per cent of cases.

“More and more people are seeking help because there is less stigma about having depression,” says principal investigator Dr. Raymond Lam, a University of British Columbia (UBC) professor and psychiatrist at the Djavad Mowafaghian Centre for Brain Health. “It’s important to find new treatments because our current therapies don’t work for everyone. Our findings should help to improve the lives of people with depression.”

The study, published today in JAMA Psychiatry, enrolled 122 patients at centres across Canada, including UBC, the Centre for Addiction and Mental Health (CAMH) and Sunnybrook. It is the largest ever study to look at the effectiveness of light therapy in non-seasonal depression.

The study received funding from the Canadian Institutes of Health Research (CIHR).

Media contact:
Sybil Millar

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Can light therapy treat non-seasonal depression?

Researchers from Sunnybrook, UBC and CAMH studied 122 people with major depressive disorder (MDD) to find out.

Patients were given one of four treatments:

  • Light box + antidepressant
  • Light box only
  • Antidepressant only
  • Neither

After eight weeks, 75% of patients given the combination of a light box and an antidepressant reported improvements in their symptoms

"Light therapy is a a low cost option with few side effects, and our findings show it could benefit many patients with non-seasonal depression" - Dr. Anthony Levitt, study co-author

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Dr. Anthony Levitt