When people reduce or stop taking their antidepressant medication, they often experience a surge in negative emotions like anxiety and low mood. A new study published in Psychotherapy and Psychosomatics suggests that these sudden emotional shifts are generally signs of a physical withdrawal reaction to the medication, rather than a return of the person’s underlying mental health condition. The research provides evidence that tracking physical symptoms like dizziness alongside emotional changes can help doctors accurately identify withdrawal.
Antidepressants are medications widely prescribed to treat conditions like depression and anxiety disorders. Patients often take these drugs continuously for months or years, during which time the body adapts to their presence. When a person decides to stop taking the medication, they typically engage in tapering, a process of gradually reducing the dose over several weeks or months.
During this period, it is common for individuals to experience a range of acute symptoms. Some of these are physical, such as dizziness, nausea, muscle cramps, and “brain zaps,” which are sudden electroshock-like sensations in the head. These physical reactions are widely recognized as direct signs of pharmacological withdrawal, a state in which the body reacts to the absence or reduced level of a drug it has become accustomed to.
However, tapering is also frequently accompanied by emotional, or affective, symptoms. These can include depressed mood, irritability, anxiety, and sudden anger outbursts. Because these emotional symptoms are nearly identical to the core features of depression and anxiety disorders, doctors face a major diagnostic challenge. When a patient feels anxious or depressed after lowering their medication dose, it can be difficult to tell whether they are experiencing a temporary withdrawal effect or a relapse, which is the return of the original mental health condition.
Making the correct distinction has major consequences for patient care. If the emotional symptoms indicate a relapse, medical guidelines generally suggest that the patient should resume taking the medication to keep their condition in check. But if the symptoms are a reaction to withdrawal, a better approach is to reduce the dose in smaller, slower steps to allow the body more time to adjust.
The scientific community has debated how frequently withdrawal occurs and how it should be classified. For example, a systematic review covered by PsyPost in 2024 argued that antidepressant withdrawal is relatively uncommon, affecting only about one in three people stopping their medication, with severe effects being rare. In contrast, other research covered by PsyPost in 2025 indicates that post-acute withdrawal symptoms can be severe and persist for months or even years.
The research team, led by Michael P. Hengartner, a professor of clinical psychology and research group leader at Kalaidos University of Applied Sciences, initiated the current study to help settle this issue. They sought to determine whether the emotional symptoms that emerge shortly after a dose reduction follow the typical periodic pattern of withdrawal or the more gradual, persistent pattern of a relapse.
“Various lines of evidence strongly suggest that rapidly emerging depressive or anxiety symptoms after antidepressant discontinuation or during tapering are manifestations of withdrawal reactions,” Hengartner, who also authored the book Evidence-biased antidepressant prescription: Overmedicalisation, flawed research, and conflicts of interest, told PsyPost. “Still, these problems are commonly interpreted and recorded as signs of mental illness relapse, which leads to inadequate treatment decisions and overestimation of the benefits of antidepressant maintenance therapy.”
To explore this, the researchers conducted a prospective longitudinal cohort study involving 32 adult primary care patients in Switzerland. The participants had been taking antidepressants for an average of 42 months and were in a state of stable remission, meaning their original depression or anxiety symptoms were no longer active. All participants were planning to discontinue their medication. The research team assessed the participants immediately before they began tapering their medication and followed up with them at two, four, six, eight, 16, and 26 weeks.
At each measurement point, participants completed standardized questionnaires to track their mental and physical states over the previous two weeks. The researchers used the Patient Health Questionnaire-9 to measure symptoms of depression and the Generalized Anxiety Disorder-7 scale to measure anxiety symptoms. To capture withdrawal effects, they used an adapted version of the Discontinuation-Emergent Signs and Symptoms Scale. From this scale, the team calculated two distinct scores: one for affective withdrawal symptoms like nervousness and mood swings, and another for discriminatory physical symptoms like incoordination, ringing in the ears, and brain zaps.
The researchers found a consistent pattern connecting the patients’ emotional states to their medication doses. Over the 26-week observation period, whenever participants’ scores for depression and anxiety went up, their scores for both emotional and physical withdrawal symptoms also tended to increase.
When participants reduced their antidepressant dose, they experienced an acute increase in depression, anxiety, and emotional withdrawal symptoms. During intervals where the dose was kept stable and not reduced further, the intensity of both anxiety and emotional withdrawal symptoms steadily declined. This wave-like pattern, where symptoms spike immediately after a dose reduction and then ease up as the dose stabilizes, is characteristic of a pharmacological withdrawal reaction. Relapses of a mental health disorder tend to develop more gradually and do not typically rise and fall in rapid response to week-to-week dose adjustments.
To test the nature of these emotional symptoms, the researchers analyzed what happened when they statistically accounted for the physical withdrawal symptoms. They reasoned that if a patient’s sudden depression was actually a relapse, it should have no direct relationship to physical withdrawal signs like dizziness or nausea.
The researchers found that accounting for changes in physical withdrawal symptoms substantially weakened the statistical link between dose reductions and spikes in anxiety and emotional withdrawal symptoms. In the case of depression scores, the association with dose reductions disappeared entirely when physical symptoms were factored in. This indicates that the physical and emotional symptoms were part of the same underlying withdrawal process.
“Rapid onset of depressive and anxiety symptoms and abatement within a few weeks after sequential dose reductions and stabilizations reflect the typical wave-like pattern of repeated withdrawal reactions, especially when these emotional problems are accompanied by discriminatory physical withdrawal symptoms such as dizziness, incoordination, visual or auditory sensory changes, muscle cramps, or nausea,” Hengartner said. “In such cases, patients are advised to reduce their antidepressant more slowly and in smaller steps to mitigate withdrawal effects.”
The magnitude of the dose reduction also played a role in symptom severity. The researchers categorized dose adjustments relative to the minimum therapeutic dose of each drug. They found that small dose reductions, defined as cutting the dose by no more than 25 percent of the minimum therapeutic amount, largely prevented the acute spikes in depression and emotional withdrawal symptoms compared to larger reductions.
“Effect sizes are variable, because they depend on the medication taken, the duration of use, the tapering steps, and the individual propensity to pharmacological withdrawal effects,” Hengartner explained. “That is, some people will barely experience withdrawal effects, some have milder and tolerable symptoms, while still others suffer severe and impairing symptoms. For the latter group, the effects have strong clinical relevance and important practical consequences.”
“We already knew from previous research that there is substantial inter-individual variability in the propensity to experience clinically relevant withdrawal reactions, but we were still surprised to see that, in some cases, even people who had been long-term on a medication with considerable withdrawal risk could discontinue treatment quite rapidly without problems, while others experienced substantial withdrawal effects,” he said. “A lot of this heterogeneity of effects remains unexplained.”
As with all research, there are a few things to keep in mind regarding this study. The sample size of 32 participants was relatively small. This limited the researchers’ ability to conduct more detailed analyses, such as comparing the specific withdrawal effects of different types of antidepressant medications or looking into how the duration of medication use affects withdrawal severity.
“This was a naturalistic study, that is, people tapered at their own pace,” Hengartner noted. “Moreover, since this was not a randomized controlled study we cannot draw firm causal conclusions. Our findings show a pattern that indicates withdrawal effects, but it is not a definite proof.”
The study also relied entirely on self-reported questionnaires to measure symptoms, without independent clinical evaluations to confirm the severity of the depression, anxiety, or withdrawal signs. Also, the gaps between measurements became longer in the later stages of the study, such as the eight-week gap between week 8 and week 16. Because withdrawal symptoms can sometimes emerge, peak, and resolve rapidly, or occasionally have a delayed onset, these extended intervals might have missed some day-to-day fluctuations in how participants responded to dose changes.
Future studies with larger groups of patients and more frequent assessments could help confirm the exact timeline of antidepressant withdrawal and test different tapering strategies to minimize patient discomfort.
“Our findings need to be replicated in a larger cohort study,” Hengartner concluded. “Moreover, a randomized controlled tapering trial is required to validate the causality of the suggested effects. Finally, we also need more research into inter-individual differences and risk factors of antidepressant withdrawal.”
The study, “Acute Affective Symptoms during Antidepressant Tapering Indicate Withdrawal Reactions Rather than Relapse: Results from a Prospective Longitudinal Cohort Study,” was authored by Michael P. Hengartner, Andri Rennwald, Oliver Senn, Stefan Neuner-Jehle, and Mark A. Horowitz.
Leave a comment
You must be logged in to post a comment.