Antidepressants are one of the most commonly taken medications in high-income countries 鈥� and are among the most controversial. Just 10 years ago, some doctors may have doubted that antidepressant withdrawal symptoms happen very much at all. Now, a study has found that these reactions occur in as many as 1 in 3 people who stop taking the medicines, although they may not always be what they seem.
Most antidepressants used today belong to a group of drugs known as selective serotonin reuptake inhibitors, or SSRIs, which are seen as an advance on earlier kinds of these treatments. Since their arrival for depression in the 1990s, doctors have increasingly offered them to people with a range of other mental health conditions, including anxiety and phobias. In England, for instance, about .
Their high use has led to concerns that the medicines are being overused. SSRIs can have side effects such as agitation and blunted emotions. Another problem is that people can find it hard to stop taking them because of the withdrawal symptoms, also sometimes called discontinuation symptoms.
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The effects can be physical, such as headaches and nausea, or mental, like anxiety and depression, which can be confused for the return of the medical condition for which the antidepressant was originally prescribed. This matters because withdrawal symptoms may only last a few weeks, but if the mental symptoms represent a genuine return of depression or anxiety, then the person may need to restart taking the medicine.
Withdrawal symptoms are thought to happen because SSRIs raise levels of a signalling molecule called serotonin within the connections between brain cells known as synapses. Indeed, it was originally thought that this is how they work, although this is now seen as too simplistic an explanation.
Regardless of their mechanism, studies in animals have shown that the body seems to adapt to SSRIs by reducing levels of other molecules in the serotonin signalling pathway, such as the receptors that serotonin normally binds to. 鈥淚f you take away the antidepressant, only the 鈥榗ounter-measures鈥� are left,鈥� says Christopher Baethge at the University of Cologne in Germany.
In the latest analysis, Baethge鈥檚 team reviewed 79 studies that had estimated how common withdrawal symptoms from antidepressants are.
The team found that 31 per cent of people experienced these effects when stopping using the medicines, although so did 17 per cent of people in placebo groups. This suggests that about 14 per cent of people experience withdrawal symptoms that are genuinely due to the drugs鈥� pharmacological actions, says Baethge.
, which suggested that more than half of all people experience antidepressant withdrawal effects after stopping. But that study included people responding to internet surveys, who may have been more likely to take part if they had been badly affected.
On the other hand, the 14 per cent figure from the latest analysis may be an underestimate, as the review included studies that hadn鈥檛 been specifically designed to identify withdrawal symptoms and so some such problems may have gone overlooked, says at the University of Southampton in the UK.
Even if some people are having withdrawal symptoms purely because of psychological expectations, that can still be difficult to cope with, says Kendrick.
Regardless of how accurate it is, the latest analysis is likely to bring the problem of antidepressant withdrawal to wider attention. 鈥淚t should be standard for every psychiatrist to inform patients, even before starting the antidepressants, about the risk of discontinuation symptoms,鈥� says team member Jonathan Henssler, also at the University of Cologne.
But the fact that such symptoms also arise in the placebo groups of the trials suggests that they can be triggered just by people expecting them to happen, he says. While doctors need to warn about the possibility of the effects, they should be careful to avoid giving people 鈥渧ery strong negative expectations鈥�, he says.
The Lancet Psychiatry
