The lights are on, but…
A while back, I stumbled across this advertisement. Essentially, it’s a pair of torches embedded in earbuds that you stick in your ears, and it’s supposed to combat seasonal affective disorder, based on the fact that the brain appears to be sensitive to light. There is some really cool stuff going on with Optogenetics, but this is something completely different. At the time, there wasn’t any peer-reviewed research for the light ear-buds, so I ignored it.
Well, that’s all changed now, with a new paper in Medical Hypotheses last month. In the pilot study, 13 participants who suffered from seasonal affective disorder were given ear-based bright light therapy (BLT – yummy), and assessed for anxiety and depression symptoms over 4 weeks. The researchers found that most of the participants reported improvements in their symptoms. The authors concluded that “it is hard to believe that our findings could be explained solely by placebo effect” Awesome, right?
Controls are there for a reason
In fact, it’s very easy to believe that their findings could be explained by the placebo effect, because they didn’t run a control condition. It seems strange, really – the authors themselves state that it would be really easy to include a placebo control; you just get a second group of matched participants and stick normal earbuds in their ears. That way, you can be sure that the results you are seeing aren’t simply due to the fact that you’re doing something to the participants, rather than nothing. Developing appropriate controls for your experiments was something that I learned in the first year of my undergraduate degree, so one has to wonder why nothing was implemented here. I trust that the researchers were well-meaning. But really, they could have done a much better job.
This month, the makers of the earbuds are going ahead with running a different study – they’re testing the efficacy of their device on alleviating jetlag symptoms. Volunteers on long-haul flights will have the option to wear the devices, and fill out a questionnaire at the end as to how better they feel. The good thing about this study is that the control conditi- oh, right. There isn’t one.
To make matters worse the sample is self-selecting, which means that the findings will be meaningless. For example, say I run a self-help course on how to motivate yourself to lose weight, and at the end of it, I give out a questionnaire to people asking how much weight they lost, and how effective they thought the course was. Now, I don’t have any expertise in this sort of motivational coaching, so it’s probably the case that some people stick to their diet and lose weight, and some don’t. Maybe most don’t. If everyone filled out the questionnaire, I’d see that this was the case. However, because it was up to the participants whether they filled out the questionnaire, it turns out that only the people that lost weight were the ones that wanted to complete it. And hey presto! I have proof that my motivational program works, because everyone said it did!
So, does transcranial brain-targeted bright light treatment work? Maybe. Maybe not. Until some robust, appropriately controlled studies are run, we just won’t know. In the meantime, here’s my own attempt at trying bright light therapy: