Depression is a major mental illness that afflicts some 17 million Americans annually. It typically requires medication and therapy, and in severe cases, a hospital stay. Public awareness and acceptance of the conditions have grown in recent decades, and thankfully, the stigma that once surrounded the illness has begun to subside.
But there’s a downside to more widespread acceptance of the disease: A tendency of some to exaggerate their mood and behavioral symptoms to garner sympathy and treatment where none may be needed.
Such is the case with the phenomenon known as Seasonal Affective Disorder or SAD, which was once thought to be an important type of depression. You can find SAD mentioned in the DSM Manual, the Bible of mental disorders among psychologists. That means it has the medical community’s official seal of approval.
SAD was long believed to be caused by an absence of light during the cold and dark late fall and winter months, especially in locales located further from the Equator.
To the usual regimen of depression treatments, doctors typically added an important element for their SAD patients: Increased exposure to light. In extreme cases, this “treatment” might include the use of a “light-box” which gave the SAD sufferer an extra 30-60 minutes of exposure to bright light, typically in the morning.
For others, “phototherapy,” as the treatment is broadly known, might include such simple measures as taking long walks in the sun, keeping the blinds and curtains open and sitting closer to the window while indoors. Some doctors would even recommend trimming the trees in the yard to make sure more sunlight is streaming toward the SAD sufferer’s house.
Sounds rather hokey, doesn’t it? It should. The latest research on SAD conducted in the UK, based on a sample of more than 30,000 depression sufferers, both moderate and acute, has completely debunked the idea that such a disease condition, in fact, exists.
The researchers asked depression sufferers about their condition as well as their country and place of residence. Try as they might, they could not find any correlation between the incidence of depression and seasonal trends, even at distances far from the Equator. The respondents certainly reported being depressed but the fluctuations in their condition didn’t seem to have anything to do with their exposure to sunlight.
The UK study echoes the findings of a 2016 study by the US Centers for Disease Control based on a telephone survey of US adults, and other studies conducted in countries like Norway with long winters and period of darkness where researchers expected to find high rates of SAD sufferers
In nearly all of these studies, the researchers weren’t trying to disprove the existence of SAD – just the opposite. In fact, the CDC researchers tried every which way to confirm the existence of SAD but despite their best efforts failed to do so.
“Depression was unrelated to latitude, season, or sunlight. Results do not support the validity of a seasonal modifier in major depression. The idea of seasonal depression may be strongly rooted in folk psychology, but it is not supported by objective data,” their study concluded.
Naturally, those that claim to have SAD – and to have benefitted from phototherapy – scoff at these studies. But, in fact, there could be other explanations. One possibility is that SAD is not actually a variant of depression, but a type of mood disorder. Some studies have suggested that possibility. It’s also possible that SAD is exceedingly rare and difficult to detect
in large population samples. A much smaller 1998 study conducted with just 8000 depression sufferers seemed to isolate a small subset with SAD symptoms
What is the science behind sunlight’s impact on depression? It’s not especially strong. Research has shown that light affects our “circadian” rhythms which mainly affect our sleep. But their effect on our moods let alone our serotonin levels is more dubious.
In fact, some SAD sufferers claim that their illness can strike them in the summer — in the full glare of sunshine. SAD defenders in the medical community – and there are still many – say it’s not just lack of light but fluctuations of light that are the problem.
In other words, there’s a SAD for all seasons.
Who knows, SAD may exist in some form, but other than anecdotally, there’s little real evidence for it. Like chronic fatigue syndrome and other dubious conditions, SAD may well be a hypochondriac’s dream, an illness one can claim to have anywhere anytime based on self-reporting alone. And since it’s fully billable, there will always be plenty of doctors willing to diagnose it for you.
SAD but true.