Science and Anti-Science on Depression

Posted on February 16, 2011 in Depression Thinking

The question gets asked at just about every convention I’ve ever attended. To be sure that I am not hallucinating, I have checked with my wife to see if she has heard the same explanation given and she has. Yet to read the blogs of some who oppose medical models for depression, you would think that there is no research to credit the position that low serotonin levels may cause depression. The picture I get of such people is of putting their fingers in their ears and shouting Neener-neener so that they do not hear the explanation. A simple search of the web using the phrase “serotonin depression” yields this description at WebMD:

One theory about how depression develops centers on the regeneration of brain cells — a process that some believe is mediated by serotonin, and ongoing throughout our lives. According to Princeton neuroscientist Barry Jacobs, PhD, depression may occur when there is a suppression of new brain cells and that stress is the most important precipitator of depression. He believes that common antidepressant medications, such as Celexa, Lexapro, Prozac, and Paxil — designed to boost serotonin levels — help kick off the production of new brain cells, which in turn allows the depression to lift.

Although it is widely believed that a serotonin deficiency plays a role in depression, there is no way to measure its levels in the living brain. Therefore, there have not been any studies proving that brain levels of this or any neurotransmitter are in short supply when depression or any mental illness develops. And while blood levels of serotonin are measurable — and have been shown to be lower in people who suffer from depression — what doctors still don’t know for certain is whether or not the dip in serotonin causes the depression, or the depression causes serotonin levels to drop.

Antidepressant medications that work on serotonin levels — medications known as SSRIs (selective serotonin reuptake inhibitors) and SNRIs (serotonin and norepinephrine reuptake inhibitors) are believed to reduce symptoms of depression, but exactly how they work is not yet fully understood.

Yep, pretty much what I hear at conferences all the time. But you only hear the insistence that “scientists have not demonstrated a link between serontonin levels and depression” from the anti-psychiatry crowd. Up to the podium they boldly walk and claim the Nobel Prize for themselves based on the same sort of reasoning that leads Creationists to dispute the Theory of Evolution. It amounts to “Science is not certain, so we have won the argument because we ~are~ certain.”

Certain, I should note, without having conducted a single experiment to the contrary.

Certain because they follow spiritual and other nonscientific teachers who, unlike scientists, don’t test their hypotheses.

Certain because they know that no one will line up to have his brain probed. And they certainly aren’t volunteering.

Certain because they cannot say “I don’t know” and “I was wrong.”

There was a time when the leading thinkers of the age were certain on these matters. They held that demons possessed us and they prescribed such cures as exorcism, confession, imprisonment, and death ((Yes, I know it sounds a lot like what contemporary Fundamentalists promote, but I am now talking about scientists not opinionated outsiders and medical professionals who take and leave what they want of science.)) . Others were certain that the mentally ill were possessed by spirits and were due the reverence of shamans or other holy men. These times were called the Dark Ages.

It was the uncertainty of Science that rescued us from these superstitions.

I personally believe that good has come of mental illness, but I have also seen the mentally ill wreck their own lives and the lives of those around them because they were Certain. Science has given us several imperfect terms to describe these states including grandiosity, racing thoughts, hypomania, and paranoia. While I think we have a lot to learn about mental illness — as much as we can from those who suffer with it — we’ve come a long ways from the days I have just described.

We don’t know the full story about depression. Only recently have medical professionals come to separate depression from bipolar disorder, recognizing them as likely being rooted in different dysfunctions of the brain. All you need to do is give a bipolar anti-depressants and you will see a different reaction than in a depression sufferer: the bipolar patient gets manic. Many people aren’t helped by anti-depressants at all. So does this show that depressions aren’t serotonin-spawned? My personal take is that there may be several different types of depression. This, I dare say, doesn’t agree with the ones attacking psychiatry because it holds out the hope that other treatments may work for other people ((Ketamine is often mentioned as a possible future replacement or augment to contemporary depression treatments, for example.)) The Scientist says “We don’t know a lot about the brain just yet and there are reasonable barriers to our understanding.” The anti-Scientist says this means we can’t trust Science to give us the answers. The reasonable human being whether a sufferer of mental illness or not realizes that this latter assessment is just wrong.