I was out last night with a friend, and he mentioned his mother’s depression. Seeing as we’re now deep into the autumn here in the UK, I asked if there was any seasonal component to this. There is. Like a lot of people, his mother’s mood takes a distinct turn for the worse in the winter. I suggested that he might consider a light therapy device to supplement the light his mother won’t be getting much of in the autumn or winter.
By coincidence, just yesterday I had been spying my own light-box on top of a filing cabinet in my office at home, wondering whether the time was right to crack it out and get using it this year. I actually started using it again today.
The device I have is a compact little number that I bought last winter. It gives off blue light. I feel it really helped maintain my mood and energy during the darker months. Unusually for me, I didn’t do any research at all before buying it. I bought it on the recommendation of a patient of mine. I had recommended light therapy to her, and she had then gone and done some research of her own. Being a thoughtful soul, she returned to my clinic some time later and presented the results of her research.
I remember her making the point that her research had revealed that light in the blue part of the light spectrum appeared to be most effective in dealing with light-related mood issues. I trusted this lady enough not to need to go and double-check this before purchasing the device she recommended.
This morning, though, I thought I’d do a bit of retrospective research regarding light therapy. Is blue light really best for treating seasonal affective disorder (SAD)? I came across a study published earlier this year in the journal Depression and Anxiety in which individuals with seasonal affective disorder were treated with blue light (of about 470 nm) with red light daily, for a period of 3 weeks [1].
60 per cent of those treated with blue light responded favourably to treatment, compared with only 13 per cent of the red light-treated group.
In the blue-light treated group, overall ratings of depression dropped by 51 per cent, compared to a 32 per cent improvement in those treated with red light.
The individuals in the study group were made up of those with SAD, as well as those with SAD in conjunction with symptoms of depression at other times in the year. Perhaps not surprisingly, those with SAD only responded better than those with more perennial depression.
In another study I found, this one from 2006, blue light outperformed red light in the treatment of SAD [2].
There does indeed seem to be evidence that light from the blue part of the light spectrum is generally most effective for treating SAD. This might be worth bearing in mind if you’re contemplating purchasing a light therapy device or considering replacing an existing one.
References:
1. Strong RE, et al. Narrow-band blue-light treatment of seasonal affective disorder in adults and the influence of additional nonseasonal symptoms. Depression and Anxiety 2009;26(3):273-8
2. Glickman G, et al. Light therapy for seasonal affective disorder with blue narrow-band light-emitting diodes (LEDs). Biological Psychiatry 2006;59(6):502-7
