A Brighter Shade of Blue | Addressing Seasonal Affective Disorder With Light Therapy

A Brighter Shade of Blue | Addressing Seasonal Affective Disorder With Light Therapy

seasonal depression

Fortunately, as with other forms of depression, treatments are available for SAD. Exercise, psychotherapy, dietary modification (and, in severe cases, antidepressant medication) are all prescribed, to varying degrees, by clinicians who encounter seasonal depression in their patients. But ever since Norman Rosenthal first began describing SAD in the 1980s, Light Therapy has been the go-to treatment.

While there’s still plenty we don’t know about the disorder (and about depression, in general), we do know that onset of SAD seems to coincide directly with a lack of sunlight. So, the easiest and most-effective solution, for the last 40-odd years, has simply been: “replace the missing light.”

For this treatment: depressed individuals spend 30 to 45 minutes under a special lightbulb every day, usually first thing in the morning, from fall to spring. The bulbs are about 20 times more potent than ordinary indoor lights – emitting 10,000 lux, and often more – effectively extending a person’s experience of “daytime.” The bulbs mimic our sun while filtering out damaging UV light, making this a safe treatment for almost everybody.

This all sounds kind of silly. I mean, a lightbulb? For depression? Turning that over in my mind feels ridiculous. It feels like a placebo… But, studies show that bulbs below the threshold of 10,000 lux seem to have no therapeutic effect whatsoever. Only these extremely-bright sun-like lights seem to melt the depression.

So there’s clearly something at work here. But what?

Consider the following:

First: Occam’s Razor. When faced with competing explanations of a phenomenon, the simplest explanation – the one which makes the fewest assumptions – is often the most correct.

Second: Did you know that scientists don’t know how Paracetamol – the active ingredient in Tylenol and the most commonly used medication in the world – actually works? I’m serious. We just don’t know! There have been some good guesses – that it inhibits COX enzymes: the creators of our bodies’ pain messenger molecules, that it blocks prostaglandin formation… but the drug interacts with so many mechanisms within the nervous system, we just can’t say with certainty why it works. We just know that it does.

It seems trivial, but these two factoids essentially sum up the history of human medicine: trial and error until something – a plant, a stretch, a change in setting – has the desired effect. And when we find that desired effect? Well, after sacrificing countless hours, dollars (and often, animal and human lives) to the search, we tend not to question those rare, positive results. And when trying to explain ourselves, the theories with fewer “moving parts” are necessarily easier to test – to prove true or false. Describing, in detail, what actually happens inside our brains during a prolonged loss of sunlight? That’s far less meaningful to an individual than preventing the consequences of that loss. If it’s as simple as replacing a light – why question it?

Thankfully, the timing of winter-pattern SAD is highly predictable. And Light Therapy lamps have exploded in popularity over the last decade, with the brightest bulbs becoming relatively affordable, even outside of an insurance plan. If you have SAD, or even just a history of depression: consider beginning Light Therapy in early Autumn. You’ll be surprised at how much a simple lightbulb can improve your day-to-day mood.

Saul Roberts

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