It’s an extremely grey (and rainy) day here in London as I write this, which reminds me that autumn and winter are not too far away. Some look to the colder, darker seasons with some trepidation, because they can find general vitality and mood take a dive at this time. At its worst, this phenomenon can manifest is what is known as ‘seasonal affective disorder’ (SAD). However, some individuals are not affected badly enough to warrant this diagnosis, and are sometimes classified as having ‘subsyndromal SAD’ (S-SAD).
I was interested to read a Swedish study published recently in which individuals with SAD and S-SAD were treated with bright light therapy [1]. In this study, individuals were exposed to 10 days of treatment in a ‘light room’. I am not able to find in the study details regarding how much time individuals spent in the light room each day. Mood, fatigue and wellbeing was rated before the light therapy, immediately after, and then a month later.
Some of the group in this study was treated immediately their symptoms became apparent. For others, treatment was delayed by 3 weeks. The idea was for this second group to act as a control group, of sorts. However, a much better control might have been exposed to a light room in which the quality of the light is known not to have benefits in the treating SAD or S-SAD.
This design flaw aside, the study did turn up some interesting results. In individuals with either SAD or S-SAD, light therapy led to improvements in scores of fatigue, daytime sleepiness and health-related quality of life. What is more, the benefits were still apparent a month after the treatment stopped.
The researchers subdivided the group into three, according to symptoms:
- mildly depressed and not sleepy
- mildly depressed and sleepy
- depressed and sleepy
The researchers go on to suggest that individuals with SAD or S-SAD symptoms might be categorised according to their predominant symptoms as follows:
- ‘simple winter fatigue’
- ‘simple winter fatigue with sleepiness’
- ‘winter depression’
I don’t know whether these terms will stick. The important thing, though, is that all three groups benefitted from the light therapy. The study does supply support for the notion that many individuals may benefit from getting more light in the winter, even if they do not have symptoms that, strictly speaking, put them in the ‘SAD’ category.
Getting more light exposure during the day in the winter is one tactic that may help. However, there are days (like today, here in London) when this is not realistic. The cold can be another barrier, as can a busy, office-based work schedule.
In such cases, a light device may prove a good investment. The one I have at home (Apollo GoLite M2) is pictured below. My subjective experience is that it’s really helped me through the winter. Nothing ‘scientific’ about my experience, of course. But then again, this does not matter to me – I feel it helps.
References:
1. Rastad C, et al. Improvement in Fatigue, Sleepiness, and Health-Related Quality of Life with Bright Light Treatment in Persons with Seasonal Affective Disorder and Subsyndromal SAD. Depression Research and Treatment. 2011:543906
