Depression and "Chemical Imbalance"

An umbrella review of the evidence dismisses the idea that inadequate serotonin levels or a "chemical imbalance" are what causes depression.  Most simply, there is no level of serotonin that we are supposed to be getting to, and it has never been clear what "chemicals" are supposedly "imbalanced" in the brain. Not that serotonin is never involved, or that creating some chemical changes in the blood which affect the brain aren't part of effective treatment of depression, they often are. It's just that the description does not universally apply and the terms are so vague as to be meaningless. 

There is some discussion of the history of the controversy and the meaning of the review in a Psychology Today column that is helpful, and includes these quotes from the lead author 

We do not understand what antidepressants are doing to the brain exactly, and giving people this sort of misinformation and prevents them from making an informed decision about whether to take antidepressants or not.

And

It is high time to inform the public that this belief is not grounded in science.

I was informed of all this from a tweet by Pradheep J Shanker @ Neoavatara that includes considerable discussion itself.

I was frankly surprised by the controversy, as I had never used the chemical imbalance explanation in my career nor heard another clinician use it.  When the phrase came up, it was from a patient or a family member who had latched onto it as a description that satisfied them. We would usually not contradict this explanation so much as redirect it to the idea that depressions are different and the mechanism in the brain is unclear. However, the medications do help a fair number of people (relatively) quickly and a lot, and a further percentage are helped partially. The medications are designed to target particular receptors, and when that is done effectively people's moods often improve.

So usually, worth a try. Sometimes they do magic. But depressions are indeed different.  Medical conditions can cause depression.  Grief can cause it. We increasingly regard anxiety and depression as related or co-occuring. I have always thought there is a hard-wired baseline of mood, with some just naturally more sanguine and others more melancholic, to use historical terms. I used the analogy of a sponge, either absorbing water and riding lower in it versus not absorbing it and riding above it.  Buoyant, if you will. But I liked it because it was quite clearly a metaphor, not an explanation.  No one was going to confuse depression with actual water absorption. (I hope.)

Because of the speed of effect - anywhere from immediately to a few weeks out and increasing over the next months, versus weeks of therapy - and my personal experience I have long been pro-medicine. We always had very limited bed space and wanted to move people along as quickly as possible, contrary to the belief of many patients and some of the public that we like to hold people indefinitely for little reason. People went off their meds, became symptomatic, came to the hospital.  We would restart meds, they would quickly get better and go home.  I was a big part of what a psych hospital does, though not everything. I also had psychotherapy for OCD for 2.5 years and learned a lot about myself and felt very grateful to be able to share deep confessional information.  But my symptoms weren't any better.  But in a couple of weeks on Prozac (it became the gold standard for OCD but this was when it was only approved for depression - I had gotten myself into a study) my symptoms were greatly reduced. And, I noticed a lightening of mood that made me wonder whether I had been mildly depressed all along. We all weight our own experience, or that of our family, higher than is quite justified for a scientific understanding.  But hey, that's the head we live in, so it looms larger.

I always thought it was just something people used as a shorthand. "Well, they are chemicals. And they change the chemicals in the brain. So they must be raising some level or correcting some imbalance, right?" And yes, being balanced sounds like a good way to think of being mentally healthy, sure. But apparently the complaint is with the pharmaceutical companies, who embraced this pop-psych explanation as a marketing assist, and with doctors who don't spend the time on a better explanation. That makes sense.  Looking at the percentages of people who understand depression in terms of chemical balance or imbalance, I can see why people get exercised about the poor understanding to the point of calling it misinformation. Odd that I was not particularly aware of the controversy at all, except that not having a TV I was not exposed to sly pharma ads capitalising on the convenient misunderstandings.