Here in the UK many of us will be acutely aware that the days are already noticeably shorter. One of the risks associated with shorter days is lowered mood or full-blown ‘seasonal affective disorder’ (SAD – also known as the ‘winter blues’. For sure, some people are more susceptible to this than others. For those who can feel ‘down in the dumps’ in the winter, I suggest be wary of the potential impact of light (or lack of it) on mood.

The issue here is that many of us, in the depths of winter, can go to work in the dark and come home in the dark. So, if we don’t get out at lunchtime, we run the risk of getting no sunlight exposure in the day at all. This, generally, is not a good state of affairs. So, one simple strategy for helping combat SAD or more muted versions of this condition is to make a commitment to getting out at lunchtime for half an hour or so. Even on the dull day the light intensity outside generally far exceeds anything you’re going to find in an office. Plus, the spectrum of the light coming from the sun is generally more conducive to having benefits for mood and wellbeing.

A year ago, almost to the day, I wrote a blog post about evidence which suggests that the ‘blue’ part of the spectrum is most effective in terms of combating SAD. This morning, I thought I’d see if the science has moved on regarding the management of SAD, and came across a review article which was published earlier this year in the Drugs and Therapeutics Bulletin [1].

One of the treatments assessed by this review was, inevitably, light therapy. The review quotes a systematic review of 8 controlled trials lasting 7-42 days that found positive results across the board [2]. It also cited another review [3] which found that bright light therapy offered considerable benefits compared to no light, but no statistically significant benefits compared to ‘control’ treatments such as exposure to sham light boxes or dim red light. The suggestion from this review here is that bright light therapy may ‘work’ primarily through the placebo effect. As I’ve stated before, if this is the case, then I don’t very much care (and neither, generally, do my patients).

However, it is possible that any real effect was not discerned as a result factors such as poor study design, inappropriate use of controls, and small participant numbers.

In short, I wouldn’t hesitate to recommend that individuals who get SAD or something similar in the winter apply some light therapy from about now and right through to well into the spring. I, myself, will be taking my own advice, for what it’s worth.

One of the reasons for writing about this review is that it mentions a type of natural treatment for SAD that I was not previously aware – negative ion generators. Negative ions are found more abundantly in the air, for instance, after a storm, in humid, plant-rich environments and by the sea. Negative ions are believed by some to have benefits on mood and wellbeing. Positive ions, on the other hand, have the reverse effect and are found abundantly in heated and air-conditioned internal environments.

In one study [4], individuals with SAD were subjected to generators which gave off high (2.7 x 106 ions/cm3) or low (104 ions/cm3) levels of negative ions. 58 per cent of those exposed to higher levels of negative ions achieved remission of their SAD, compared to 15 per cent in the other group (the result was statistically significant).

One other natural approach worth trying concerns vitamin D. For more about this, see this post.

References:

1. Management of seasonal affective disorder DTB 2009;47:128-132

2. Golden RN, et al. The efficacy of light therapy in the treatment of mood disorders: a review and meta-analysis of the evidence. Am J Psych 2005;162:656-62

3. National Institute for Health and Clinical Excellence. Depression in adults (update) 2009

4. Terman M, et al. Treatment of seasonal affective disorder with a high-output negative ionizer. J Altern Complement Med 1995;1:87-92