A new review study that challenges long-held public beliefs about the cause of depression has caused a stir in the psychiatric community, but it hasn’t advised people to stop their antidepressant treatment.
That serotonin Theory of Depression: A Systematic Umbrella Review of the Evidence was published in the magazine Molecular Psychiatryand found that after reviewing a collection of previously published studies examining the link between serotonin levels and depression, there was little evidence to support the established idea that chemical imbalances were the cause.
The questions underlying the study examine why the chemical imbalance theory of depression remains the standard despite the alleged lack of evidence in both the medical community and the general public, and how this theory became dominant in the first place.
dr Joanna Moncrieff, a professor at University College London and a 30-year consultant psychiatrist for the UK National Health Service, is one of the lead authors of the study. She spoke to The Independent about the research, its impact and the response the study has received from the medical community and the public.
What does the study actually say?
Put simply, the study found that there was insufficient evidence to support the prevailing view among the public and some medical institutions that a chemical imbalance in the brain causes depression. As a result, the study questions the wisdom of physicians who prescribe antidepressants to patients without a more solid understanding of the drugs’ long-term health effects.
“The theory of the chemical imbalance of depression is still held by scholars, and the serotonin theory in particular has formed the basis of considerable research efforts over the past few decades,” the study concluded. “The general public widely believes that depression has been convincingly demonstrated to be the result of serotonin or other chemical abnormalities, and this belief shapes how people understand their moods, leading to a pessimistic view of the outcome of depression and negative expectations.” regarding the ability to self-regulate mood, suggests that depression is the result of a chemical imbalance, also influences decisions about whether to take or continue antidepressants, and may discourage people from stopping treatment, potentially leading to lifelong dependence on these drugs .
In a blog post after the publication of the study and in her interview with The Independentstressed dr. Moncrieff states that individuals who are taking antidepressants such as SSRIs and are considering whether or not to continue their treatment should do so under the continuous guidance of a physician and should only discontinue them in a controlled, supported, and gradual process.
In other words, people should not respond to this study by suspending their antidepressant treatment, but should continue to work with their doctors to address their mental health and any underlying causes that may be contributing to their depression.
Academic Response to Research
Despite these warnings, the study has met with some opposition from the medical community. A slew of doctors have spun their wagons around the use of antidepressants, arguing that it is well understood in the medical community that depression is caused by a confluence of factors, not just a chemical imbalance, and that these treatments are still available effective in treating these symptoms.
dr David Curtis, honorary professor at University College London’s Genetics Institute, told the Science Media Centre: “This paper does not present new evidence, it only reports on findings that have been published elsewhere and it is certainly not news that depression is not caused by them “low serotonin levels”. The notion that depression stems from a “chemical imbalance” is outdated, and the Royal College of Psychiatrists wrote that this was an oversimplification in a statement published in 2019.
“It’s also not like SSRI antidepressants increase serotonin levels. Their immediate effect is to alter the balance between levels of serotonin inside and outside neurons, but their antidepressant effects are likely due to more complex changes in neuronal function that occur later as a result of it. It is very clear that people suffering from a depressed suffer from an illness, have an abnormality in brain function, although we do not yet know what it is, and that antidepressants are effective treatments for major depression, but interventions such as exercise and mindfulness are not. It is important that people with major depression are not discouraged from doing so to receive appropriate treatments that can make a huge difference to them and those around them.”
dr Moncrieff said she wasn’t surprised by the response to the study and agreed that the theory presented was probably not news to academia but likely to the general public.
“Some psychiatrists have said quite openly, no, there is no real evidence for it [the serotonin theory of depression] for a while, but nobody wanted to highlight it or highlight it to the public in any way,” she said.
In addition, Dr. Moncrieff acknowledges that antidepressants can benefit people who take them, whether through blunting of intense emotional states caused by depression or through the placebo effect. However, she cautioned that the medical community should better understand what the drugs actually do if they are to be used.
“It’s important for people to understand that we don’t really know what the effects — the mental and behavioral — of these drugs are,” she said. “They have mental and behavioral effects, one of which is likely to be emotionally numbing. what may or may not be useful. I would guess that it doesn’t make sense for most people in the long term, but there may be some people in a crisis or emergency who feel this would be something helpful.”
She also said that antidepressants “definitely” have placebo effects and that these effects have been confirmed in clinical trials.
“We know that the majority of the response people have in antidepressant trials is the placebo response,” she said. “There’s research showing that people who suspect they’re taking an active drug do significantly better than those who suspect they’re taking a placebo, even when they’re not actually taking the active drug.”
How did antidepressants become the norm for treating depression?
The serotonin theory of depression was introduced in the 1960s when doctors first theorized that there was a link between serotonin levels and individuals experiencing depressive states. This remains the prevailing theory until the 1990s, when pharmaceutical companies began promoting SSRIs — which increase brain serotonin levels — directly to consumers, at least in the US. They also market the drugs directly to doctors, which Dr. Moncrieff contributes to its dominance as the primary treatment for depression.
“In the ’90s and early ’00s, there was a huge marketing effort for doctors — you walked into a doctor’s office and there were Prozac cups and pens everywhere,” she said. “And I think that’s another reason the doctors didn’t really question it, they were just bombarded with this idea that this is the fact, this is the situation. If you repeat something enough, people like to believe it. It really is.”
However, as the UK National Health Service states in its guidelines, SSRIs are also used specifically because their short-term side effects are not as severe as those of other antidepressants. like dr Moncrieff noted the drugs are effective in helping people suffering from depression, but she argues that the results of the study make it clear that they alone cannot be the basis for fighting depression. While the medical community largely agrees with this sentiment, this message is not as well known to the general public.
Following the paper’s publication, a TikTok user named Liv Speakman — who graduated from Oxford with a major in psychology and neuroscience — praised the research in a video that garnered more than 460,000 views. She argued that it was a positive step in combating pessimism in people living with depression, who believe they are doomed to suffer their affliction forever.
Her comments section was filled with laypeople expressing confusion and some concern at the news. They asked if this meant their antidepressants were ineffective and if they should continue treatment. In a follow-up video, she explained that SSRIs and other antidepressants are still useful and that people should continue to work with their doctors to manage their depression. Ms Speakman compared the drugs to painkillers and said people take painkillers not because they don’t have enough painkillers in their bodies, but because the drugs numb the pain and allow them to go about their lives.
Another content creator, Rebecca Watson, debunking a YouTube channel and website called medical misinformation Skepchickwas more critical but focused primarily on news websites with headlines suggesting that antidepressants were not effective in treating depression.
She quoted a Daily Mail Story that read with one line: “Have millions taken antidepressants for decades with harmful side effects – although there is no scientific evidence, are they doing what they claim? Some experts have suspected it for years.”
“To reiterate, everything I just read to you is wrong. So incredibly, stupid, annoyingly wrong. ‘There is no scientific evidence (antidepressants) do what they claim?’ Wrong,” she said in a recent YouTube video. “There are HUNDREDS of randomized controlled trials showing that antidepressants are more likely to help people with depression compared to placebo. There is no ‘new research’ to disprove this. No.”
Reporting covering complex health and science issues has often been derided by experts for misrepresenting and misleading the public, either by misunderstanding the facts or by using sensationalism to lure readers.
In fact, says Dr. Moncrieff that she undertook the work specifically to highlight the fact that what the public knows and what experts know about depression are incongruent and that correcting this fact through further study is a priority for communicators and researchers alike should be.