Ever heard of the winter blues? There’s a reason some people start feeling sad during the colder months: seasonal affective disorder (SAD). Light therapy, or a “happy box,” is often used to help combat symptoms of SAD. The light box is like a screen and is the size of an average desktop computer.
Researchers are currently working to see if light therapy can also help treat depression that’s part of bipolar disorder. According to the National Institute of Mental Health, bipolar disorder is a brain disorder that causes unusual shifts in mood, energy, activity levels and the ability to carry out day-to-day tasks. The idea behind light therapy is that it replaces lost sunshine with a daily dose of bright white artificial light.
In order to determine its usefulness in treating bipolar disorder, researchers at the Feinberg School of Medicine at Northwestern University studied 46 patients who had at least moderate bipolar depression.
Half of the participants received bright light therapy, while the other half received dim red placebo light. In addition to the bright or red light, participants were instructed to keep taking their regular medication during the study. To ensure lack of bias, the placebo group was instructed not to research light therapy or discuss the color of their light treatment with anyone else in the study.
To begin, all participants were told to place the light about 1 foot away from their face for a 15-minute session. Every week, they lengthen the amount of exposure time until it reached 60 minutes a day.
According to psychiatrist Dorothy Sit, lead author of the study, participants didn’t have to stare directly at the box during the allotted exposure time, they simply needed to be in front of it.
While patients with SAD typically do light therapy as soon as they wake up, Sit’s research found that early morning light therapy could trigger people with bipolar disorder into a manic phase.
Due to this finding, she had the participants engage in light therapy midday, between noon and 2:30 p.m.
After four to six weeks, Sit found that 68% of the participants who received the bright light therapy achieved remission of depression compared to the 22% of participants who received the red placebo light.
Bright light patients who achieved remission were able to return to work and function as their normal selves.
As the results of this study are highly preliminary, Sit and other researchers say people with bipolar disorder should not try light therapy on their own.
Al Lewy, one of the pioneers of light therapy used to treat SAD, said that because light therapy can trigger hypomania, it should be conducted under a doctor’s supervision.
"If there's the slightest chance that a patient will switch into a manic episode, then their doctor can be there to treat them," he said.
Psychiatrist Ken Duckworth, medical director of the patient advocacy group National Alliance on Mental Illness, said that this study "offers a glimmer into a new pathway for treatment” for people with bipolar disorder.
Mood stabilizers and other medications that are used to treat the manic phase of bipolar disorder may not be effective in treating the depressive phase, Duckworth said. According to him, people with bipolar disorder "spend most of their time on the depressive end of the spectrum."
For now, Sit is waiting to see her findings duplicated in the future to uncover how the light affects the body's circadian rhythms at different times of day, and how that affects bipolar symptoms.
Learn more about light therapy for bipolar disorder here.