Around 13% of Americans take antidepressants, and their use is growing around the world. In the UK, the prescription of antidepressants has doubled over the past 10 years. The long-term use of the drugs is also increasing, year on year. In 2000, around 5 million Americans had been taking antidepressants for five years or more. By 2018, this had increased to 15.5 million. At the same point, almost 25 million adults had been taking antidepressants for more than two years, a 60 percent increase from 2010.
You might assume that such a widely used treatment has been proven beyond doubt to be effective, just as widely used painkillers like paracetamol or aspirin have been shown beyond doubt to be beneficial. You might also assume that such a widely used treatment has minimal side effects and risks, or at least that these are significantly outweighed by its positive effects.
Unfortunately, neither of these assumptions is true. The evidence for the benefits of antidepressants is ambiguous, whereas there is increasing evidence that their risks (especially their addictive potential) have been underestimated.
In 2018, a study was published which was reported by many media outlets as proving that antidepressants were effective, and vindicating their widespread use. This study, by researchers at the University of Oxford, reviewed over 500 international trials, and found a consistent benefit of antidepressants compared to placebos. On average, most antidepressants were 50% more likely to have some effect than placebos.
However, on closer inspection, the results weren’t as significant as reported. The study used the Hamilton Depression Scale, on which participants can have an overall score of 0 to 52. Antidepressants only reduced the severity of depression an average of around 2 points. So although antidepressants were more likely than placebos to have some effect, this effect was, as the authors themselves reported, “mostly modest” (1).
Other recent studies of antidepressants have had ambiguous results. A 2008 meta-analysis, led by Dr. Irving Kirsch at Harvard, showed no significant difference between leading antidepressants and placebos (2). Since then, the findings of this study have been reproduced several times, by the original group and other researchers. (It is important to note, however, that these studies didn’t find that antidepressants had no benefits, since placebos themselves can have significant effects.)
A 2019 UK study of the effects of sertraline (a selective serotonin reuptake inhibitor, or SSRI) found no effect on the symptoms of depression within 6 weeks, and just a minor effect after 12 weeks. However, participants did report some reduction in anxiety and some improvement in quality of life (3). Some clinical trials have suggested that antidepressants can be effective in cases of severe depression (although they are most often prescribed for mild depression, where they are mostly ineffective). However, a 2019 review of the evidence questioned the use of antidepressants to treat major depressive disorder, concluding, “The benefits of antidepressants seem to be minimal and possibly without any importance to the average patient with major depressive disorder” (4).
Is Depression Caused by a Lack of Serotonin?
It’s perhaps not surprising that the evidence for antidepressants is ambiguous, since the causal mechanism by which most are presumed to work is questionable. SSRIs are based on the assumption that depression is associated with lower levels of serotonin in the brain. However, this assumption is dubious: There is no evidence that people with depression have less serotonin than others, and no evidence that depression can be induced in people by decreasing serotonin. The idea of depression as caused by a ‘chemical imbalance’ that can be corrected by chemicals has captured the popular imagination, but has no factual basis.
Writing in the British Medical Journal in 2015, psychiatrist David Healy described how the myth of a connection between depression and serotonin was propagated during the 1990s by drug companies and their marketing representatives, not long after tranquilizers started to be abandoned due to concerns about their addictiveness. In fact, as Healy states, earlier research in the 1960s had already rejected a connection between depression and serotonin, and shown that SSRIs were ineffective against the condition. However, bankrolled by the pharmaceutical industry, the myth of a depression as a “chemical imbalance” that could be restored by medication quickly caught on. (5)
However, you might say that even if the benefits of antidepressants are small — and even if they are little more than a placebo, which still has some beneficial effects — surely that still justifies their use? Surely if there is evidence that they can cause a 2-point decrease in depressive symptoms on a scale of 0-52, or decrease anxiety, that’s good enough?
With every medicine, benefits should be weighed against risks. It is well known that SSRIs may have some significant side effects, such as fatigue, weight gain, emotional flatness, loss of libido, insomnia, and agitation. But what has become increasingly clear from recent research is that one of their most serious adverse effects is withdrawal symptoms.
The American Psychological Association has stated that antidepressants are "not habit-forming," and that withdrawal symptoms usually only last one or two weeks. But the evidence suggests otherwise. In a 2016 study from New Zealand almost three-quarters of 180 patients reported withdrawal symptoms from antidepressants, with 45% reporting some level of addiction. Many patients in this study complained that they hadn’t been given sufficient warning of the addictive potential of the drugs, or the withdrawal effects. (6) A 2019 UK study found that 56% of patients who stopped taking antidepressants suffered withdrawal symptoms for several weeks or months, with 46% describing them as severe. The researchers concluded that these withdrawal symptoms were the reason why so many patients take antidepressants for long periods, since they are often confused with a relapse, leading to a new prescription. As one of the researchers, James Davies, commented, “This new review of the research reveals what many patients have known for years – that withdrawal from antidepressants often causes severe, debilitating symptoms which can last for weeks, months or longer.” (7)
Such findings have led to a change in the UK’s National Institute for Health and Care Excellence (NICE) guidelines. Originally, these stated (like the APA) that withdrawal symptoms from antidepressants were slight and short-lived. But in October 2019 this was updated to warn of severe and lengthy withdrawal symptoms.
The Medical Model of Depression
Perhaps the fundamental reason why antidepressants are so widely prescribed and used is that they fit with the ‘medical model’ of mental illness, which has become the standard view in western culture. This model sees depression as a medical condition which can be “fixed” in the same way as a physical injury or illness. In a more general way, this fits with our culture’s materialistic assumption that the mind is just a product of the brain, and our mental functioning can be entirely explained in terms of neurological factors. (See my book Spiritual Science for further discussion of this.) If you feel depressed, it must be because there is something wrong with your brain.
This is a dangerously simplistic way of viewing depression, and as the overuse of antidepressants shows, it has had harmful effects. In reality, there are many possible causes of (or at least contributory factors to) depression: an unsatisfactory social environment, relationship problems, the frustration of basic needs (for self-esteem, belonging, or self-actualization), a lack of meaning and purpose in life, oppression or unfair treatment, negative or self-critical thinking patterns (related to low self-esteem), a lack of contact with nature, poor diet, and so on.
How will antidepressants affect any of these factors? It’s true that, in some cases, a more positive mood may motivate people to make lifestyle changes. On the other hand, antidepressants may make people less likely to directly address these issues, partly because they may not relate them to their low moods, and partly because their drug-induced apathy and emotional flatness will reduce their ability to take effective action in their lives.
Some depressed people clearly gain some benefit from antidepressants. There is no doubt that they can sometimes be beneficial, particularly if used sparingly and temporarily. In particular, they appear to beneficial in cases of severe depression. And as I mentioned above, even if they function largely as a placebo this isn’t necessarily an argument against their prescription, since the placebo effect can be very powerful. (See my previous post on placebos.)
But the negative effects of antidepressants — in particular, their withdrawal symptoms — appear to outweigh their benefits. If there was, say, a antibiotic or cardiac medication whose efficacy was so ambiguous, and whose negative effects were so severe, it’s difficult to imagine that it would be on the market for long.
It seems scandalous that hundreds of millions of human beings around the world are suffering addiction and adverse reactions to powerful psychotropic drugs which give them little or no benefit. Surely it is time to give more attention to more holistic treatments. What most depressed people need are not chemical interventions, but lifestyle interventions, therapies, and strategies that will enable them to make changes to the way they think about themselves, their behaviour, and their lifestyle. They don’t need drugs; they need more meaning and purpose, better relationships, new ways of thinking, more exercise, more contact with nature, and so on.
In countries such as the UK, Australia, and New Zealand, guidelines for doctors already recommend talking therapies such as counselling and cognitive behavioural therapy for people with mild to moderate depression. Other recommendations are for exercise and reducing alcohol consumption. Recent research has also shown that mindfulness and ecotherapy (contact with nature as therapy) can be effective against depression.
It’s time to accept that we are suffering an epidemic of the use of antidepressants, at massive expense to our societies — most importantly, at massive expense to the well-being of millions. It’s time we devoted more attention to more effective holistic therapies, which have no withdrawal symptoms, and are much more likely to address the core issues which give rise to depression.