Antidepressant Withdrawal Threshold & Tinnitus Study

A New Study Identifies a Key Threshold for Antidepressant Withdrawal Symptoms

For patients with tinnitus, misophonia, and hyperacusis, antidepressants like selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are often prescribed to manage co-occurring anxiety or depression. Discontinuing these medications can be challenging, and the risk of withdrawal reactions is not well quantified. A new preprint from Swiss researchers offers data on when and for whom these symptoms most often occur.

Authors Rennwald, Horowitz, Senn, Neuner-Jehle, and Hengartner followed 32 primary care patients who had been on antidepressants for at least six months and were in stable remission. Over six months, they tracked symptom changes using an adapted Discontinuation-Emergent Signs and Symptoms Scale (DESS) as patients tapered their medication. They standardized doses relative to the minimum effective dose—the lowest dose proven effective for treating depression or anxiety—to create a common metric across different drugs.

Their central finding is specific: withdrawal symptoms significantly increase when the dose drops below 75% of that minimum effective level.

The 75% Threshold: Where Symptoms Typically Begin

The researchers analyzed symptom changes across seven assessment intervals during tapering. They found a clear pattern: intervals where the dose was reduced to a level above 75% of the minimum effective dose, or where no reduction occurred, were generally associated with a decrease in symptoms. This is likely because patients remained in a therapeutic range or were stable.

Intervals where the dose dropped below the 75% threshold, however, were strongly associated with an increase in withdrawal symptoms. After adjusting for potential confounders like depression relapse, the odds of a clinically relevant symptom increase during such intervals were 3.2 times higher compared to intervals with no dose reduction.

The adjusted incidence rate for clinically relevant withdrawal reactions was 32%. For severe reactions, it was 11%. The team calculated that about 60% of the risk for clinically relevant symptom increases during the study could be attributed to pharmacological withdrawal effects, not to a return of the original illness.

Implications for Hearing Health Patients

For patients on antidepressants for conditions related to tinnitus or hyperacusis, this study has practical implications. Drugs commonly used in this population, such as sertraline, paroxetine, fluoxetine, or venlafaxine, all have different pharmacokinetics and potencies, but the 75% threshold provides a general guide.

The data show that even small reductions within this lowest dose range can trigger significant reactions. This argues against a simple, linear tapering schedule and supports a hyper-gradual, patient-specific approach at the end of discontinuation. Clinicians should be aware that a patient reporting new or worsening physical or emotional symptoms during a taper—especially when doses are very low—may be experiencing withdrawal, not a relapse of their auditory condition or associated anxiety.

Study Limitations and Preprint Status

This prospective longitudinal cohort study offers valuable real-world data, but it has limitations. The sample size of 32 patients is relatively small. The cohort was in stable remission, which may not reflect patients who are still symptomatic. The study also grouped different antidepressant classes together, though it standardized doses to address this.

Most importantly, this is a preprint shared on medRxiv. It has not undergone peer review, the standard process where independent experts scrutinize the methods, analysis, and conclusions. The findings are promising and align with existing neuropharmacological models, but they should be considered preliminary.

Future research with larger, more diverse populations, including those specifically with hearing health conditions, will be needed to confirm these incidence rates and the precise 75% threshold across all antidepressant types.

Source:
Incidence of antidepressant withdrawal reactions: A prospective longitudinal cohort study in primary care patients (medRxiv preprint, 2026-05-15)