We’ve all heard the theory — a chemical imbalance in your brain causes depression.

Although researchers have known for years this not to be the case, some drug companies continue to repeat this simplistic and misleading claim in their marketing and advertising materials. Why the FTC or some other federal agency doesn’t crack down on this intentional misleading information is beyond me. Most researchers now believe depression is not caused by a chemical imbalance in the brain.

How did we come to this conclusion? Through years of additional research. But now some are jumping on the next brain bandwagon of belief — that depression is caused by a problem in the brain neuronal network.

Jonah Leher makes the case in today’s Boston Globe:

In recent years, scientists have developed a novel theory of what falters in the depressed brain. Instead of seeing the disease as the result of a chemical imbalance, these researchers argue that the brain’s cells are shrinking and dying. This theory has gained momentum in the past few months, with the publication of several high profile scientific papers. The effectiveness of Prozac, these scientists say, has little to do with the amount of serotonin in the brain. Rather, the drug works because it helps heal our neurons, allowing them to grow and thrive again.

Okay, I’m game… But Leher fails to bring any sort of balance to his article. It’s another love letter to the brain scientists studying in this field, but ignores the decades’ worth of research showing that non-medical treatments are also effective in treating depression. Like, you know, psychotherapy.

The obvious answer is that psychotherapy also helps in some way to help “heal our neurons.” Which begs the question — if healing our neurons is key, there are likely dozens of possible ways to do so. Why only focus and mention the medical cures?

Because of Leher’s deification of the power of medicine:

The progress exemplifies an important feature of modern medicine, which is the transition from a symptom-based understanding of a disease – depression is an illness of unrelenting sadness – to a more detailed biological understanding, in which the disease is categorized and treated based on its specific anatomical underpinnings.

This would be true if mental disorders were pure medical diseases. But they are not and have never been. They are human constructs of aberrant behavior or emotions. They are by no means universal (although some of the big ones, like depression, can be found in most human societies).

This new scientific understanding of depression also offers a new way to think about the role of drugs in recovery. While antidepressants help brain cells recover their vigor and form new connections, Castren says that patients must still work to cement these connections in place, perhaps with therapy. He compares antidepressants with anabolic steroids, which increase muscle mass only when subjects also go to the gym.

Yeah, because that’s how all medical treatments work, right? You need some encouragement for a drug to take effect? This is nonsense. Drugs either work or do not, they do not need to be “cemented” to the brain through therapy.

It also contradicts all of the extensive body of research that shows psychotherapy that works for depression without any drug whatsoever. What magical process occurs simply through talking with another human being that can change the very structure of your brain’s neuro networks?

Perhaps one day science will tell us. But these love letters in the media to neuroscientists have got to stop. Neuroscience will one day provide us the “keys to the kingdom” of understanding our brains. But until studies are done on humans (most of the studies Leher cites in his article — but fails to mention but once — are done on rats, not humans; a rat’s brains and a rat’s “depression” may be nothing like ours), we should approach this most recent theory with a healthy dose of skepticism.

Many researchers staked their professional careers and reputation on the theory that a “serotonin imbalance in the brain” caused depression. This was incorrect. This may also be the case of this latest fad brain theory to see the light of day and in another decade, may also be proven to be equally untrue. Until then, folks (especially the media) should keep a healthy skepticism about rat brain studies and new brain theories on depression. And ensure they account for or have a reasonable explanation for the effectiveness of psychotherapies such as cognitive-behavioral therapy (CBT) for depression.

Read the full article: How Prozac sent the science of depression in the wrong direction

Another Brain Fad for Depression?