Key Takeaways
- If you stop taking SSRIs suddenly, you may experience withdrawal symptoms known as SSRI discontinuation syndrome.
- Common withdrawal symptoms can include flu-like symptoms, restlessness, and electric shock sensations.
- SSRIs cause changes in the brain, and when stopped, there will be fewer serotonin receptors for a while.
If are taking a selective serotonin reuptake inhibitor (SSRI) antidepressant, it is important to talk to a doctor before you stop taking your medication. If you stop taking your antidepressant suddenly, you may experience withdrawal symptoms known as SSRI discontinuation syndrome.
“SSRI withdrawal symptoms are not uncommon. They can start when people abruptly stop taking antidepressants. People can have flu-like symptoms, trouble sleeping, nausea, imbalance, electric shock sensations, and restlessness,” says Rehan Aziz, MD, a psychiatrist at Hackensack Meridian Health and associate professor of psychiatry and neurology at the Hackensack Meridian School of Medicine.
Learn more about what happens if you quit taking an SSRI abruptly, some 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 they are having a relapse and request to be placed back on SSRIs.
Verywell / Emily Roberts
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 various 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:
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 withdrawal symptoms.
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.
Recap
Many SSRIs have a relatively short half-life, meaning they leave the body quite quickly. When antidepressant levels drop suddenly, it may lead to symptoms of withdrawal. SSRIs also cause changes in serotonin receptors in the brain, so when SSRI levels (and by extension, serotonin levels) drop abruptly, it takes some time for the body to adjust.
Common SSRI Withdrawal Symptoms
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:
- Chills
- Diarrhea
- Difficulty walking
- Dizziness
- Fatigue
- Headaches
- Impaired concentration
- Insomnia
- Irritability
- Lightheadedness
- Nausea/vomiting
- Paresthesia (burning, prickly, or skin-crawling sensations)
- Shock-like sensations (sometimes called brain zaps)
- Vertigo
- Visual disturbances
- Vivid dreams
The mnemonic FINISH is often used to summarize the symptoms that people typically experience. It stands for Flu-like symptoms (such as tiredness, achiness, sweating, and headache), Insomnia (along with vivid dreams or nightmares), Nausea (which may sometimes be accompanied by vomiting), Imbalance (dizziness, vertigo, lightheadedness), Sensory disturbances (‘brain zaps’), and Hyperarousal (anxiety, irritability).
Symptoms typically begin two to four days after abruptly stopping an SSRI that has been taken regularly for at least one month. In some cases, people can experience withdrawal symptoms after missing a dose of an SSRI with a short half-life. Research suggests that around 70% of people taking SSRIs skip doses occasionally, so it is not uncommon for people to experience some withdrawal symptoms from time to time.
While these symptoms can be uncomfortable, they are rarely severe. Most people only experience mild to moderate forms of SSRI discontinuation syndrome.
Severe Symptoms
In some cases, people may experience more severe symptoms such as:
How to Prevent SSRI Withdrawal Symptoms
Research suggests that around 50% of people experience SSRI withdrawal symptoms when they stop taking a selective serotonin reuptake inhibitor. These symptoms typically last around two weeks, but may persist for longer for those who have been on SSRIs for many years.
Taking your medication at the same time each day can help minimize the risk of experiencing withdrawal symptoms. If you do miss a dose of your medicine, take it as soon as you remember unless it is almost time for your next dose. Don’t take a double dose to make up for your missed dose.
If you’ve missed a dose or stopped your medication and begin having withdrawal symptoms, Dr, Aziz recommends resuming your regular dose and talking to your doctor.
The best way to manage [withdrawal symptoms] is to restart the medication and, if desired, work with a doctor to slowly discontinue it. Otherwise, discontinuation symptoms last for about one to two weeks.
—
REHAN AZIZ, MD, PSYCHIATRIST
Tapering Your Dose
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.
To lower the risk of SSRI withdrawal symptoms, speak with a doctor about gradually weaning you off your drug.
Typically, tapering off over one to two weeks would be reasonable if treatment has lasted less than eight weeks. After six to eight months of treatment, you may need to taper off over six to eight weeks.
Your tapering schedule will depend on the medication you are taking and how long you have been taking it. Your doctor may also adjust your schedule as needed depending on your symptoms.
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.
It is also a good idea to check in with a doctor a few weeks after completely stopping 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.
Recap
Tapering your SSRI dose over a period of time is often the best way to minimize the effects of SSRI discontinuation syndrome.
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Gabriel M, Sharma V. Antidepressant discontinuation syndrome. CMAJ. 2017;189(21):E747. doi:10.1503/cmaj.160991
U.S. Food and Drug Administration. Prozac: Fluoxetine capsules, usp; fluoxetine oral solution.
Horowitz MA, Framer A, Hengartner MP, Sørensen A, Taylor D. Estimating risk of antidepressant withdrawal from a review of published data. CNS Drugs. 2023;37(2):143-157. doi:10.1007/s40263-022-00960-y
Bhat V, Kennedy SH. Recognition and management of antidepressant discontinuation syndrome. J Psychiatry Neurosci. 2017;42(4):E7-E8. doi:10.1503/jpn.170022
American Psychiatric Association (APA). Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text revision. Washington, D.C.; 2022.
Additional Reading
Fava GA, Gatti A, Belaise C, Guidi J, Offidani E. Withdrawal symptoms after selective serotonin reuptake inhibitor discontinuation: A systematic review. Psychother Psychosom. 2015;84(2):72-81. doi:10.1159/000370338
Harvey BH, Slabbert FN. New insights on the antidepressant discontinuation syndrome. Hum Psychopharmacol. 2014;29(6):503-16. doi:10.1002/hup.2429
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