In her new book psychiatrist Dr Joanna Moncrieff challenges the reductionist approach to depression which asserts that it is due to a chemical imbalance in the brain that needs to be treated with drugs
Over the last few decades we have started to believe that our feelings are a mechanical product of the chemical activity in our brains. Doctors have told us that serotonin, for example, is our ‘happy chemical’ and that depression is caused by a lack of it. Dopamine is said to be associated with excitement and risk taking. Endless media stories, online articles, books and commercial products repeat these ideas. You can now buy an extensive range of jewellery in the shape of the serotonin molecule that comes with messages such as ‘happiness and satisfaction’, ‘happiness and wellbeing’ and ‘happiness will grow’.
This reductionist view that posits human feelings and behaviours as manifestations of brain processes has become standard. We have forgotten that there are other ways to understand our emotions. This has led to an impoverished approach that regards negative feelings as emotions to be subdued or obliterated, rather than something we can learn from and use as an inspiration for change.
As I explain in my book, the reductionist view is like trying to understand the content of a painting by analysing the canvass or the paint. This will not reveal that the Mona Lisa is a painting of a woman who is half smiling. The physical structure of the painting does not disclose its meaning. We need a brain to be the intelligent, feeling humans that we are, but our thoughts and feelings have meaning and are not reducible to brain mechanisms.
Until the early 1990s people generally thought of moods and emotions as the way we respond to our circumstances. When people were asked about likely causes of depression, they would say ‘divorce’ or ‘unemployment’. This view was changed over the course of the 1990s by massive promotional campaigns run by the pharmaceutical industry, supported by the medical profession. These campaigns were deliberately designed to change people’s minds about the nature of depression. The ultimate aim was to persuade people to take antidepressants and, in order to do that, the industry needed to overcome people’s natural reluctance to use drugs to numb and suppress their feelings.
The ‘chemical imbalance’ saga
Mind-altering, prescription drugs had got a bad reputation by the end of the 1980s due to the scandal over benzodiazepines; drugs such as Valium, Librium and Zanax were doled out liberally from the 1960s onward and people were reassured these new drugs were not addictive or dependence-forming, like their predecessors, the barbiturates. This turned out to be false and, by the 1980s, it became apparent that a significant proportion of the population had become dependent on these drugs and suffered significant withdrawal effects when they tried to stop them. This made people particularly wary about using drugs to address emotional problems.
Step up the concept of the ‘chemical imbalance’! The idea that depression was caused by an underlying abnormality of brain chemicals, such as serotonin and noradrenaline, had been constructed by psychiatrists and researchers back in the 1960s. Although a large, US government-funded, research programme conducted in the 1970s failed to show evidence of such abnormalities, the idea persisted. Pharmaceutical companies revived it in the 1990s to help persuade people that taking their new range of drugs for psychological problems, the SSRI’s (selective serotonin reuptake inhibitors), was not like taking a benzodiazepine. It was not like taking a mind-altering drug at all; in fact, it was taking a ‘treatment’ for an underlying disease.
The trouble is this exercise in public manipulation was never based on science. In 2022 colleagues and I published a paper in which we systematically surveyed all the main areas of research on serotonin and depression since the 1990s and showed that none of them provided convincing evidence of a link.
Despite this, the message that depression was caused by a chemical imbalance that could be corrected by medication was stunningly successful. Prescriptions for antidepressants rose by more than eight times (that’s 800%!) since 1990 and more than doubled since 2011. By 2019, almost one in five of the population of England was prescribed them. The number of people taking anti-depressants on a long-term basis also increased, so that by 2019 two thirds of people taking antidepressants had been taking them for more than a year.
Do antidepressants really work?
But is this situation necessarily a problem? Numerous experts claim that antidepressants ‘work’ and that it does not matter how. Like so much that is claimed about mental health and the brain, this claim needs interrogating. When people claim antidepressants ‘work’ they mean they reduce scores on a depression scale of 54 points by around 2 points more than a placebo in clinical trials. This difference is miniscule and easily accounted for by the fact that people can often guess whether they are getting the real drug or the placebo due to the side effects and other noticeable changes produced by antidepressants. These create higher expectations in people taking the real drug and we know that people’s expectations have a powerful effect on their outcome.
In one study, for example, the antidepressant was no different from the placebo, but people who guessed they were taking the antidepressant (regardless of whether they were actually getting it or the placebo) showed a 5-6-point greater reduction in their depression scores compared to those who guessed they were taking the placebo.
Even if the two-point difference is a real effect, it is unlikely to make any significant difference to people’s lives or to compensate for the adverse effects of antidepressants, including sexual dysfunction. Also, rather than representing the effect of a targeted action on some underlying, biological mechanism, it is more likely to be a manifestation of the way that antidepressants change our normal emotions. Most antidepressants have a numbing effect, reducing the intensity of both positive and negative feelings. Some people might welcome a degree of numbing when they feel desperate, but many do not like the idea.
The numbing of emotions highlights how antidepressants subtly change our normal feelings and mental experiences. This is a consequence of the fact that they change our normal brain chemistry and activity. Taking a drug that numbs your emotions by changing the normal state of the brain is a very different prospect from taking one that you think is going to remedy your serotonin deficit. What antidepressants do and how they impact on our feelings does and should influence our decisions about whether we take them or not.
Read the complete article in issue 113.