A man in his 30s gradually began to notice a disturbing pattern about his mental state: Every year around October, he became sad almost all the time.
He got to the point where he was constantly taking days off work, feeling hopeless and unable to cope.
When summer rolled around, he felt great and reverted to his old self.
Several years later and after a visit to a Winnipeg psychiatrist, he got his diagnosis: Seasonal Affective Disorder, or the aptly named SAD, for short.
It's a condition that scientists didn't even identify until the 1980s when they figured out that certain people are more sensitive to the lack of light associated with fall and winter months.
The brains of these people, according to researchers, are lacking certain chemicals during the darker months -- hormones/neurotransmitters that affect mood, ability to sleep and the body's circadian rhythm or biological clock.
So what happened to the patient?
"For the past three or four winters, he hasn't had any episode of depression," says Dr. Michael Harrington, a psychiatrist and assistant professor at the University of Manitoba.
The treatment? Harrington prescribed antidepressant medication from October to March. From April to September, he stops the medication, since his SAD vanishes during those months.
The diagnosis is pretty clear for many people, says Harrington, who is fascinated by SAD and the latest science surrounding it. He admits the condition is still cloaked in mystery as the medical community tries to learn more about it.
Harrington will talk about SAD on Wednesday during a public lecture (and question-and-answer session) at the U of M's Health Sciences Centre campus. It's part of Med Talks, a health-themed speaking series that costs $10 for admission.
The Free Press recently spoke to Harrison about SAD:
Free Press: How common is SAD?
Harrington: Three per cent or even a higher number of people have this. That's affecting more than 500,000 Canadians every year.
FP: That's a lot of people. Are most of these cases of SAD mild?
MH: No. It definitely has a significant impact on their lives. It affects their work, their relationships and their ability to enjoy.
FP: How can you tell the difference between SAD and feeling blue because the weather conditions make it cold, gloomy and hard to get around?
MH: We notice a lot of biological changes that would be more than just some sadness related to the limitations of winter. For example, it's very common to see changes where people need a lot more sleep and are very tired in the morning. It's common to see people with appetite changes -- they're eating a lot more food and seeing substantial changes in their body weight
FP: Is SAD a new condition?
MH: It was described in ancient times even by the earliest doctors. However, it's only been in the latter half of the 20th century that the science came together to find out about the biological processes that influence it.
It's only been since the 1980s that it's been best recognized.
FP: How many patients have you treated with this disorder?
MH: It would number in the hundreds.
FP: Is there a definitive test that would diagnose SAD?
MH: When someone has a pattern of SAD, it is important to get blood work that can exclude certain illnesses that can masquerade in that way. That can include thyroid illness, other hormone problems and even diabetes. However, there is no blood test for SAD.
FP: What are the most exciting developments in SAD treatment?
MH: New antidepressants are being developed that work, in part, on the melatonin system that is implicated in your daily biological clock. Most interestingly, light therapy. Thirty minutes a day in the winter can protect against SAD.
FP: How does it do that?
MH: It affects us through our eyes that go to the brain. It's the interaction of certain types of photoreceptors in our eyes linked to serotonin production. These photoreceptors aren't used for vision, they're used for regulation of the daily biological clock. By having very intense light early in the day, there's an interaction with those circuits in the brain which have an effect on all of the pathways that are important for moods.
FP: What are the names of the brain chemicals associated with SAD?
MH: Serotonin, norepinephrine and dopamine. These are linked to all types of depression, not just SAD.
FP: Is there not a way of measuring these neurotransmitters?
MH: There are tests. They aren't clinically useful at this point because it is a great range that people have. And it's not just the level in our bloodstream. It's very molecular level changes in the brain cells in a way that we don't have a way of directly measuring yet.
FP. Do you administer light therapy (light boxes that mimic outdoor light) to patients?
MH: No. Patients administer it to themselves in their own homes -- 30 minutes at the beginning of the day, typically while eating breakfast or reading the newspaper.
FP: What type of light (SAD light box) should someone use?
MH: They are available at even mainstream retailers. The size isn't important, but there are some important technical parameters. A light has to be quite bright -- 10,000 lux -- which is a quite high level of brightness. And it has to have the right spectrum.
FP: Can tanning beds treat SAD?
MH: Tanning beds aren't effective for this type of treatment. It's very important to have your eyes covered in tanning beds, so they won't work at all. The UV spectrum is very dangerous to the eyes.
FP: It's all about the eyes in this therapy. Correct?
MH: We have every reason to think that the way the light affects depression is through the eyes and through those brain circuits which are connected to the eyes.
FP: Is SAD generally recognized in the medical community?
MH: Yes. Unfortunately, the majority of people with SAD have not been identified by their doctors, probably because patients aren't educated about (the condition) and don't know to ask for help.
FP: Is it frustrating to deal with skeptics?
MH: It can be difficult. People are getting a lot of messages from society that the problem they are having is a choice. It's obvious to any patient in that condition that if there was a choice not to be depressed, they would easily make that choice.
FP: Do you prefer to treat SAD with light therapy rather than antidepressants?
MH: Not necessarily. I like to minimize medication as much as I can, but I don't look at it as a failure when someone is well controlled on medication and without side effects.
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