This article discusses what happens if you quit taking an SSRI abruptly, some of the withdrawal symptoms you might experience, and how to prevent SSRI discontinuation syndrome.

What Is SSRI Discontinuation Syndrome?

Selective serotonin reuptake inhibitors (SSRIs) are a class of drug commonly used to treat depression and some forms of anxiety. The drugs help normalize brain function in people with certain mood disorders by increasing the amount of serotonin in the brain. While beneficial, one of the downsides is that some people may experience a form of withdrawal called SSRI discontinuation syndrome when treatment is stopped. This syndrome most commonly occurs when the medication is stopped abruptly and can manifest with symptoms that seem very much like the depression and anxiety the SSRI was being taken to treat. People experiencing SSRI discontinuation syndrome often believe that they are having a relapse and request to be placed back on SSRIs.

Why SSRI Withdrawal Symptoms Occur

Serotonin is a type of chemical, called a neurotransmitter, whose purpose is to deliver messages to and from brain cells. By modifying this process, the chemistry in the brain can be regulated in a way that typically improves depression or anxiety. The assorted SSRI drugs used to treat mood disorders have similar mechanisms of action, but varying degrees of drug half-life. This term describes how long an active drug molecule stays in the bloodstream before being expelled from the body. If a drug has a short half-life, it will require frequent dosing to maintain the ideal concentration in the blood (and, therefore, the desired effect). If it has a long half-life, it will remain in a steady state for longer and be less prone to ups and downs. Most SSRIs have short half-lives. Common SSRI medications used to treat depression include:

Celexa (citalopram) Lexapro (escitalopram) Paxil (paroxetine) Prozac (fluoxetine) Zoloft (sertraline)

Of these, Prozac has the longest half-life and, when stopped, will gradually clear from the bloodstream. The others, by contrast, have a short half-life and, when stopped, will drop off abruptly. When this happens, the person taking them may experience disconcerting or even profound symptoms of withdrawal.

Changes in the Brain

Drug half-life is only part of the reason for SSRI discontinuation syndrome symptoms. When used over a period of time, SSRIs can cause changes in the brain that affect serotonin receptors. As a result of these changes, the brain will “down-regulate” the number of receptors in response to the increased volume of serotonin. It’s a physiological balancing act meant to prevent the overstimulation of brain cells. When treatment is eventually stopped, there will be fewer receptors than before and a short-term deficiency of serotonin activity. The body will typically correct this, but there will be a period of adjustment until the system normalizes.

What People Experience

The most common symptoms of SSRI discontinuation syndrome are described as either being flu-like, or feeling like a sudden return of anxiety or depression. They can include:

Catatonia (a state of unresponsiveness) Chills Depersonalization (a detached, out-of-body experience) Diarrhea Difficulty walking Dizziness Fatigue Headaches Impaired concentration Insomnia Irritability Lightheadedness Muscle pain (rare) Nausea/vomiting Paresthesia (burning, prickly, or skin-crawling sensations) Psychosis Shock-like sensations Suicidal thoughts Vertigo Visual disturbances Vivid dreams

While these symptoms can be uncomfortable, they are rarely severe. Most people only experience mild to moderate forms of SSRI discontinuation syndrome.

Prevention of SSRI Discontinuation Syndrome

Around 20% of people taking Paxil, Zoloft, Celexa, or Lexapro will experience some degree of withdrawal following termination of treatment, lasting anywhere from one to three weeks. For those who have been on SSRIs for many years, the symptoms may persist for longer. For more mental health resources, see our National Helpline Database. To lower the risk of SSRI withdrawal symptoms, speak with a doctor about weaning you off your drug gradually. Typically, if treatment has lasted less than eight weeks, tapering off over one to two weeks would be reasonable. After six to eight months of treatment, you may need to taper off over the course of six to eight weeks. Don’t try to make up your own tapering schedule or stop taking your recommended treatment without consulting a doctor. Work with them to create a plan, as they will better understand the limitations and potential hazards of any drugs you are taking and can help guide you accordingly.

A Word From Verywell

If want to stop taking your antidepressant or lower your dose, always talk to your doctor first. SSRI discontinuation syndrome can be unpleasant, so gradually tapering your dose can help minimize the chances of severe symptoms.  It is also a good idea to check in with a doctor a few weeks after you have completely stopped taking your antidepressant. You should also reach out to a doctor if you notice the return of any symptoms of anxiety and depression in the weeks and months after you have stopped taking your antidepressant medication.