Is Depression Caused by a Chemical Imbalance?

Doubtless you have been puzzled. Recently, the media, and that means all the media, breathlessly reported that some researchers had discovered that depression is not caused by a serotonin deficiency, that is, by a chemical imbalance in the brain. 

Cue the outrage. Apparently, all of those selective serotonin reuptake inhibitors were not as powerful as claimed. And all those hundreds of millions of prescriptions should not have been written. 

Naturally, to be especially clear, I know nothing about medical treatments for depression. So I have hesitated to comment on the new findings.

And yet, I have now found a column, written by a psychiatrist named Max Pemberton, which explains what the research does and does not show. Pemberton writes for The Daily Mail and we are happy to see that one of our favorite newspapers has offered some sage commentary on the study-- what it does and does not demonstrate:

Last week, the debate was reignited with the publication of research into the 'serotonin theory of depression': the idea that low mood is caused by low levels of the brain chemical serotonin.

The new research claimed to have debunked this theory and, because the most commonly prescribed antidepressants work by boosting serotonin levels in the brain, this led to much discussion about whether antidepressants are effective.

And yet, Pemberton continues, the research did not study the effectiveness of anti-depressants.

It is important to say from the outset that this research didn't actually look at antidepressants at all, just whether low serotonin was the cause of depression.

And besides, the chemical imbalance theory is a simplification, not a scientific fact. In truth, physicians do not believe it.

But really this is irrelevant. The idea that depression is simply a chemical imbalance in the brain is clearly a gross over-simplification and I don't know a single doctor who believes it.

Now, for some useful information. First, that there is no single thing called depression. The condition is associated with a number of conditions, and its causes are complex.

Considering that depression might be associated with psychosis, which seems to be a brain disease and with bipolar illness which seems to be a metabolic disturbance, this is a high useful qualification.

Besides, as we have often remarked, and as we discovered during the pandemic lockdowns, reducing the amount of social interaction we have produces something like depression. And no serious psychiatrist thinks that anyone can solve the problem by taking a pill.

The reality is that depression is an umbrella term — it's a symptom rather than a medical condition on its own — and there are many, many different causes. It seems likely that it's caused by a complex interaction of biological, psychological and social factors.

It would make sense, therefore, that rather than one treatment, you would need a number of different treatment options depending on the individual. In the fight against depression you need an arsenal of weapons — and antidepressants are a useful part of that.

Needless to say, drug companies have been touting the virtues of Prozac and the other SSRIs. Their marketing has been sustained by the wild-eyed claims of psychiatrists like Peter Kramer who argued that Prozac could change your personality-- for the better or the worse, he was not very clear.

And yet, as a psychiatrist who has prescribed antidepressants, Pemberton affirms that in many cases they really do work. 

I am no fan of the pharmaceutical industry or the way it attempts to manipulate its data to make drugs appear more effective. I also think antidepressants are too readily prescribed and access to psychotherapy is far too limited.

But that doesn't mean drugs don't work when they are prescribed properly. For many people they undoubtedly do work.

And yet, while we are questioning motives we should recognize, as Pemberton explains, that the researchers who seem to have debunked a theory that no one believes are what used to be called anti-psychiatrists:

It's important to note that several of the academics involved in this latest research are so-called 'critical- psychiatrists'.

In other words, they are academics who disagree with the idea of prescribing medication for mental illness, so their conclusions are, perhaps, unsurprising.

So, they have a vested interest in the research. One is somewhat surprised to hear that anyone still believes that mentally ill patients should not be treated with medication. The theory had some followers, like R. D. Laing and David Cooper, during the 60s and 70s. It produced calamities, so no real psychiatrists were ever willing to apply it. In truth, psychiatrists who were practicing before the advent of neuroleptics and different classes of antidepressants categorically believe that these drugs have helped their patients.

As it also happens, SSRIs have been overprescribed, especially since many of the prescriptions have been written by general practitioners:

The answer is complicated. It is true that, in some situations, antidepressants may be given out too readily by harassed GPs who have just ten minutes to help patients with complex social problems.

Unfortunately, the mania about drugs obscures the fact that you can make considerable progress in overcoming your depression by improving your relationships. And, dare we add, aerobic conditioning exercises also have a demonstrably positive impact on depression:

However, there is no pill or potion on this planet that is going to make your bullying boss change their ways, or your bored wife love you, or remove the stress of looking after your ailing elderly parents.

That is not to say these situations aren't awful but, actually, feeling down about these sorts of things is normal, not pathological. It's not an illness, it's what medics call 'c**p-life syndrome'.

Sometimes it is right to feel bad about a situation. Feeling depressed or anxious are not necessarily signs of illness:

Certainly, social situations can trigger a depressive illness, but all too often people who are just responding to unpleasant, stressful and awful situations in a perfectly normal way are given a prescription and pushed out the door.

And then, in Great Britain, thanks no doubt to the wonders of the National Health Service, much severe depression goes untreated:

The flip side of this is that while antidepressants are being overprescribed in some quarters, in others, depression is woefully under-diagnosed and under-treated.

A horrifying study by the London School of Economics a few years ago showed that while mental illness accounts for nearly half of all ill health in the under-65s, only a quarter of people in need of treatment actually get it.

Further research conducted by Aberdeen University showed that GPs failed to diagnose major depression in half their patients, with the result that they went untreated.

There are large swathes of the population who are suffering in silence. Some of the highest rates of under-diagnosis occurred in older men — who also have the highest rates of suicide.

A confidential inquiry into suicide showed that fewer than 10 per cent of people who killed themselves had been referred to mental health services in the previous 12 months. How appalling.

For people who are struck down with depression, whether low serotonin is or is not the cause doesn't really matter.

People who are depressed need treatment. It might include medication, but it is better prescribed by people who are qualified in psychopharmacology. And treatment should involve more than just pills:

Such people need quick, individually-tailored, expert help, whether that's in the form of antidepressants, psychotherapy, social support or a combination of these things.

The fact that the evidence clearly shows this doesn't happen for the majority of people with depression is the real scandal and that is what warrants our attention.

Now, you have a better sense of what is involved in the so-called research.