Evolutionary psychologist Paul Andrews has an unusual take on depression and anti-depressants.
Andrews, an assistant professor at McMaster University in Hamilton, Ont., thinks that depression, miserable as it is, serves a positive role, much as fever does in fighting infection.
He argues that the lethargy, lack of appetite, sleeplessness and rumination that accompany depression help people focus on and ultimately solve their problems.
"Depressed mood states seem to promote an analytical processing style," Andrews said, that helps people break complex problems into smaller bites.
We try to derail that process at our peril.
In an analysis of 46 previous studies published last month in the journal Frontiers of Evolutionary Psychology, Andrews found that patients who used anti-depressants were twice as likely to relapse when they stopped compared to those who were on placebos.
He thinks that's because the drugs alter levels of two key mood-regulating chemicals: serotonin and norepinephrine. He likens the effect to holding a spring down with your hand. When you remove your hand, the spring bounces up even higher.
Andrews found that relapse rates were highest for drugs that have the greatest impact on these neurotransmitters. Twenty-one percent of patients on placebos relapsed within three months compared to 43 to 75 percent of patients on anti-depressants.
Most depressive episodes come in response to specific events such as a breakup or job loss, Andrews said. Depending on the study, 15 to 40 percent of people say they have had major depression - the kind in Andrews' study - but almost everybody has had milder forms.
What does this mean for patients? "It looks like, if you can get better without taking anti-depressant medication, you'll have a much better chance of not having a relapse," said Andrews, who is not a clinician.
"Physicians," he said, "should be telling their patients about this possibility before they get on the drugs so at least they understand what they're getting into."
Andrews didn't study talk therapies, but said they "don't mess with the brain chemistry, so they shouldn't have any negative effects of the sort I've been studying."
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