ne of the impacts of the Covid lockdowns since March 2020 has been a widespread worsening of mental health, with anxiety and depression the most common symptoms reported. Running parallel to this, the prescription of antidepressants in England has climbed to record levels, according to the NHS Business Services Authority. In the final three months of 2020, there was a reported 6% increase in prescription rates. According to the government, 17% of the population were taking an antidepressant in 2017-18, the last year for which figures are available. This rise probably reflects both the increase in diagnosis of depression and anxiety because of the pandemic, and the restricted availability of talking therapies during lockdowns. While antidepressants play an important role in treating depression and anxiety, it’s essential at this time of increasing usage rates to address how people will ultimately stop treatment. There are no reliable figures for the proportion of people suffering withdrawal reactions after stopping antidepressants, or for the fraction who have severe problems. Discontinuation problems vary according to dose, treatment duration and the individual antidepressant. From my experience, both personal and vicarious, I would estimate that most people – a small majority – have only mild symptoms when stopping, and some, albeit very few, may have no symptoms. A good percentage of people will have noticeable symptoms that are at best disturbing and unpleasant, and a small minority will have severe and even disabling symptoms that may linger for many months or even longer. In my professional life I speak to many patients considering antidepressants about their potential benefits and shortcomings. I also help develop guidelines on their optimal use and on how best to stop treatment with them. Perhaps more importantly, I have also taken antidepressants myself and have gone through the process of stopping them. My personal experience broadly reflects what I hear from patients: sometimes stopping is easy, sometimes it’s awful. In 2019, I co-authored a paper in the Lancet Psychiatry that recommended some patients may need to reduce their prescriptions over the course of many months, down to as little as one-fortieth of their original dose, before giving them up entirely. Previously, standard advice was to stop taking antidepressants over the course of up to four weeks. Some official guidelines introduced in the past few years now reflect the findings of our paper and recommend what is known as “hyperbolic tapering”. If taken at low doses or for a few weeks or months, antidepressants seldom cause any significant problems when patients stop. However, most current guidelines suggest continuing antidepressant treatment for six to nine months after getting better to reduce the risk of a relapse into the original condition. This advice means more people may suffer some kind of withdrawal when they finally try to reduce their dose. In medical textbooks and official guidelines, I am informed that stopping antidepressants can lead to a “discontinuation reaction”. This reaction is usually described as “mild and short-lived”. I know from personal experience that, if you don’t do it right, stopping antidepressants can be a pretty horrible experience. Dizziness, nausea, anxiety, panic, mood changes, sweating, agitation, insomnia, nightmares and electric shock sensations are all common symptoms. None are physically dangerous or life-threatening, but neither are they pleasant. This withdrawal syndrome is readily distinguishable from a return of the original depression or anxiety because dizziness, nausea and electric shocks (known as “zaps”) are not symptoms of either condition. As well as a prolonged reduction schedule, the dose of antidepressant needs to be lowered in a way that gradually and evenly decreases its pharmacological effects. It may seem logical to reduce from, say, 20mg a day to 15mg, to 10mg and then to 5mg, and then stop. However, for complex reasons related to something called the law of mass action, such a reduction schedule will produce ever larger reductions in the effect of the antidepressant. Withdrawal symptoms may then get progressively worse with each step down and some people will find it very difficult to stop if using this method. A dose reduction schedule that looks something like this – 20mg a day, 10mg, 7.5mg, 5mg, and then 2.5mg and even down to 1.25mg and then to 0.625mg – is an example of hyperbolic tapering. It is thought to be the most effective way to reduce the severity of discontinuation symptoms or even avoid them altogether. The difficulty, though, is that it may sometimes be practically difficult to measure the small doses needed at the end of the taper. Patients have been doing their own hyperbolic tapering for many years, having discovered, often by trial and error, that it is the best method. I have read online accounts of people breaking open their antidepressant capsules and reducing the amount of medication inside by one grain each day. Needless to say, it is important to always talk to your prescriber before making any decisions about treatment, and the dosing schedules I give here are for illustrative purposes only. Antidepressants do work for most people and they remain important treatments for depression and anxiety, alongside behavioural and psychological interventions. Nonetheless, anyone thinking of starting an antidepressant should do so in the knowledge that they can sometimes be difficult to stop, and that slow, hyperbolic tapering may be required to minimise any withdrawal symptoms. Prof David Taylor is director of pharmacy and pathology at the south London and Maudsley NHS foundation trust