Bright Light Therapy Can Ease Depression
"Bright-light therapy" can help people with major depression, particularly when used with an antidepressant, according to new research at the University of British Columbia in Vancouver.
In an eight-week study of 122 people with major depression, the scientists found that those who were treated with either a bright light box or a combination of light box therapy and an antidepressant had more improvement in their symptoms than people treated with a placebo.
The study participants were divided into four groups. The first group was given a fluorescent light box to use for 30 minutes upon waking each day in addition to taking Prozac. The second group was given a light box and placebo pill, and the third group was given Prozac and a placebo device called an ion generator. The ion generator was deactivated so it would not generate ions, but it was set up so that it would still hum when turned on. The final group was given both the placebo pill and placebo device. To further protect the objective of the study, the researchers told the participants they were comparing light and ion treatments.
Then, the researchers assessed the severity of the participants’ depression at the beginning and at the end of the study using a standard scale used in psychiatry.
The results, published in JAMA Psychiatry, showed that 76 percent of the participants who had both light therapy and an antidepressant had their symptoms improved by 50 percent or more. That level of improvement was seen in only half of those who had light therapy and the placebo pill, 33 percent of the participants who received the placebo ion device and the placebo pill, and in 29 percent of the people who took the antidepressant and the placebo device.
Additionally, the researchers looked at the number of participants whose depression went into remission at the end of treatment. The antidepressant and light therapy group had 9 percent of its patients go into remission, while there was 44 percent remission in the light therapy and placebo pill group and 30 percent remission in the placebo device and placebo pill group. Only about 19 percent of the people who took the antidepressant and used the placebo device went into remission.
The researchers speculate that the bright light therapy may work for people affected by Seasonal Affective Disorder (SAD), by resetting their inner biological clock or circadian rhythms.
Another theory suggests that light affects brain chemistry by acting on the same neurotransmitters that antidepressants act on, such as serotonin, dopamine, and noradrenaline.