Few practices in mental health are debated more than the long-term use of antidepressant medications, which are prescribed to roughly one in nine adults in the United States, according to data from the Centers for Disease Control and Prevention.

A reassessment began in 2019, when two British researchers published a study that found that 56 percent of patients suffered from withdrawal symptoms when they stopped antidepressant medications and that 46 percent of those described their symptoms as severe.

The findings made headlines in Britain and had a powerful ripple effect, forcing changes to psychiatric training and prescribing guidelines. And they fed a growing grass-roots movement calling to rein in the prescription of psychotropic drugs that has, in recent months, gained new influence in the United States with the rise of Robert F. Kennedy Jr. as health secretary.

A new study, published on Wednesday in the journal JAMA Psychiatry, makes the case that these warnings were overblown. The authors of the new paper found that a week after quitting antidepressants, patients reported symptoms like dizziness, nausea and vertigo, but that they remained, on average, “below the threshold for clinically significant” withdrawal.

Dr. Sameer Jauhar, one of the authors, said the new analysis should reassure both patients and prescribers.

“The messaging that came out in 2019 was all antidepressants can cause this and this can happen in this proportion of people, and that just doesn’t survive any scientific scrutiny,” said Dr. Jauhar, a professor of psychiatry at Imperial College London.

He criticized the earlier study for including data from online surveys as a quantitative measure, for failing to control for the placebo effect, and for failing to distinguish between various types of antidepressants. These methodologies, he said, led to inflated estimates of withdrawal.

“The public concern was based on the data that was presented,” he said. “And maybe if the evidence had been this evidence, you might not have had things escalate to that degree.”

The new analysis, based on 50 studies with more than 17,000 subjects, is not an apples-to-apples comparison. The authors did not try to measure the prevalence of withdrawal symptoms or their severity. Instead, they used a research tool to track individual symptoms present in patients after stopping an antidepressant, and compared them to the symptoms of patients who had stopped taking a placebo.

Patients who had quit antidepressants were 5.5 times as likely to report dizziness, 6.4 times as likely to report vertigo and 3.1 times as likely to report nausea compared to placebo. But on average, the number of withdrawal symptoms had risen modestly, by only one compared with placebo, which is not considered clinically significant.

The report is unlikely to settle the debate over withdrawal from antidepressants.

Even before the JAMA paper had been published on Wednesday, critics online were laying out their arguments against it — principally, that too many of the trials the team included were short-term efficacy trials, in which subjects had been taking the medications for no more than eight weeks.

“If you are looking at people on the drugs for eight weeks, you are not going to find withdrawal,” said James Davies, one of the authors of the 2019 study that found high rates of withdrawal symptoms. “It’s like saying cocaine isn’t addictive because we did a study on people who had only been taking it for eight weeks. “

Dr. Davies, an associate professor of psychology at the University of Roehampton in England, said he worried that the findings, “if read uncritically,” would “cause considerable harm by significantly downplaying the effects of real-world antidepressant use.”

“According to their conclusions, the tens of thousands of people online who are struggling with severe and protracted withdrawal aren’t really in withdrawal,” he said. “There are real people out there on the ground that aren’t making up the fact that they are in a lot of pain coming off these drugs.”

One reason for the confusion is that, for decades, researchers showed little interest in antidepressant withdrawal and did not conduct rigorous long-term trials. Physicians recognized withdrawal symptoms in some patients, but viewed them as transient, usually resolving after a few days. But attention to the subject is rising along with the controversy.

In 2024, a team of German researchers published a review of 79 studies in The Lancet that concluded that one in three patients quitting antidepressants reported withdrawal symptoms — and so did one in six patients quitting placebo. Accounting for the placebo effect, 15 percent of patients experienced withdrawal symptoms like dizziness, headache, nausea and insomnia. Three percent of patients experienced severe withdrawal, they found.

Dr. Jonathan Henssler, one of the authors of the 2024 study, said that he had hoped the work would contribute balance and calm to the discussion, but that had not happened.

“Unfortunately, the emotional charge of the discourse and the strong polarization of reception both in the public media and in scientific discourse have not substantially diminished,” he said. He said he worried, particularly, about the way findings would be conveyed to the public.

“Anyone who communicates in an exaggerated and alarmist manner, in the worst case,” could leave patients braced for a negative outcome, he said, “with the risk that they then close themselves off from potentially helpful treatment or maintain antidepressant treatment only out of fear.”

Dr. Allan H. Young, one of the authors of the JAMA paper, said he had seen “a flare-up in concern about this from many patients” in his clinic after the 2019 analysis received widespread press coverage.

“I’ve certainly had patients at my clinic thinking that they shouldn’t go on antidepressants when that was what I would recommend,” he said, adding that patients should be reassured by the new analysis.

“It’s quite clear that you can have some effects when stopping antidepressants,” he said, “but these are a limited number, and they do seem to decline over time.”