SSRIs and SNRIs are antidepressants commonly used to treat anxiety. Here’s how they differ and what you can expect.

Many people experience anxiety from time to time, and there are many strategies to find relief. But when anxiety begins to affect your day-to-day, more long-term solutions are needed.

Antidepressant medications are often used to treat symptoms of anxiety, depression, and other mood or mental health disorders. Two of the most common antidepressants are selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs).

SSRIs and SNRIs increase the production of brain chemicals that help regulate your mood and stress response. This tends to make the medications especially effective for easing anxiety.

Understanding what makes these drugs work, how they differ, and their side effects can help determine whether an SSRI or an SNRI is right.

SSRIs and SNRIs are two classes of antidepressant drugs that commonly treat:

The main difference between the two is that SSRIs affect only serotonin levels in the body. SNRIs impact both serotonin and norepinephrine levels. They also can have different side effects.

SSRIs and SNRIs are popular options for treating anxiety.

When your body’s serotonin or norepinephrine levels are either too high or too low, your mood can be affected. This can make you feel more anxious or worried and may even lead to more severe anxiety disorders or types of depression.

Taking an SSRI or SNRI helps balance these brain chemicals, significantly reducing anxiety symptoms to help you face stressful situations better.

There’s no consensus on which is more effective in treating mental health conditions. SSRIs tend to be more widely used than SNRIs and are often considered the first line of defense. According to a 2021 review, side effects tend not to be as severe for SSRIs compared with SNRIs.

SSRIs and SNRIs can be equally effective options for treating anxiety disorders. A 2018 review comparing the medications found that there are no major differences. But reviewers did find that both drugs are most effective in treating social anxiety disorder.

Also, a 2008 review of SSRIs and SNRIs research showed that SNRIs might be more effective in treating severe depression symptoms. These differences tend to be modest and aren’t true for all SNRI drugs. Talking with a doctor can help you determine which antidepressant is best for you.


SSRIs increase levels of serotonin in the brain. Your body produces serotonin to help regulate your mood. When serotonin levels become imbalanced — either too low or too high — it can affect your mental health. Low serotonin levels, in particular, can cause depression, anxiety, and other mood disorders.

SSRI antidepressants can boost serotonin levels, which can help ease symptoms to treat these conditions.

Common SSRIs include:


SNRIs increase the levels of two mood-affecting neurotransmitters in the brain: serotonin and norepinephrine.

Like serotonin, norepinephrine plays a role in how you feel. Norepinephrine specifically impacts your fight, flight or freeze response, influencing how you react to stressors or threats.

Low norepinephrine levels can also affect your sleep quality, concentration ability, and attention span.

Common SNRIs include:

What are they?Selective serotonin reuptake inhibitorsSerotonin-norepinephrine reuptake inhibitors
How they workincrease serotonin levels in the brainincrease serotonin and norepinephrine levels in the brain
What are they prescribed for?help treat symptoms of anxiety, depression, and other mental health conditionshelp treat sleep disorders, increase concentration, and treat symptoms of anxiety and other mental health conditions
Common prescription drugsCelexa, Lexapro, Luvox, Paxil, Pexeva, Prozac, Sarafem, Viibryd, ZoloftCymbalta, Effexor XR, Fetzima, Pristiq, Savella
Common side effectsAnxiety, sleep problems, sinus infections, rashes, sweating, fatigue, sexual dysfunctionAnxiety, sleep problems, sinus infections, rashes, sweating, fatigue, nausea, dry mouth, dizziness, sweating, headache
Rare side effectsVision problems, irregular heart rate, allergic reactions, changes in weight, suicidal thoughts, serotonin syndromeConstipation, sexual dysfunction, changes in appetite, increased blood pressure, liver problems, serotonin syndrome

Few medications are without risk, and there are several possible side effects associated with SSRIs and SNRIs. Some of these are similar. Others are unique to each drug.

Common SSRI side effects include:

In rare cases, SSRIs can also cause:

Common side effects of SNRIs include:

  • anxiety
  • sleep problems
  • sinus infections
  • rashes
  • sweating
  • fatigue
  • nausea
  • dry mouth
  • dizziness
  • sweating
  • headache

SNRIs may also cause rare side effects, such as:

  • constipation
  • sexual dysfunction
  • changes in appetite
  • increased blood pressure
  • liver problems
  • serotonin syndrome

SSRIs and SNRIs are two types of antidepressants used to treat depression, anxiety, and other mood disorders. They boost the production of specific neurotransmitters. SSRIs specifically target serotonin, while SNRI drugs affect serotonin and norepinephrine levels.

Because they help balance these brain chemicals, both medications are especially effective in treating anxiety and anxiety-related disorders.

While SSRIs and SNRIs can help treat various mental health conditions, taking them can lead to potential side effects, including increased anxiety, sleep problems, and skin rashes. Other risks depend on the specific drug.

If you’re experiencing symptoms of anxiety, depression, or other mood disorders, using an SSRI or SNRI drug may help. Consider talking with a doctor for guidance, as both types of drugs need to be prescribed.

A doctor can help you determine whether an SSRI or SNRI is right for you and recommend other treatments.