Antidepressant medications are a first-choice option for treating major depressive disorder (MDD), according to guidelines from the American Psychiatric Association. They can also help to treat anxiety conditions, including generalized anxiety disorder.

There are different types of antidepressants, based on how they work within the brain. Some are better for treating certain conditions and symptoms. But they all come with potential side effects.

Generally, each type causes somewhat different side effects, but there can still be some variance within a single type.

People can also respond differently to antidepressants. Some people may have no troubling side effects, while others may have one or more serious side effects. This is why you may need to try a few different medications before you find the right fit.

Here’s a look at the main types of antidepressants and some of the side effects commonly associated with them. If you take a certain type, you probably won’t experience all of the side effects associated with it. You might also experience other side effects, including some serious ones, that aren’t listed here.

SSRIs affect serotonin, which is a neurotransmitter that plays a role in many things, including your mood. Neurotransmitters act as chemical messengers within your body.

When your brain releases serotonin, some of it is used to communicate with other cells, and some of it goes back into the cell that released it. SSRIs decrease the amount of serotonin that goes back into the cell that released it, leaving more available in your brain to communicate with other cells.

Experts aren’t completely sure about the role serotonin plays in depression. But many believe that low levels of serotonin are a contributing factor.

SSRI antidepressants include:

SSRIs are the most common choice for treating MDD, but they can also help with:

Common side effects

The more common side effects of SSRIs include:

  • headaches
  • nausea
  • trouble sleeping
  • dizziness
  • diarrhea
  • weakness and fatigue
  • anxiety
  • stomach upset
  • dry mouth
  • sexual problems such as low sex drive, erectile dysfunction, or ejaculation problems

SSRIs are more likely than some antidepressants to cause sexual side effects. They can also increase appetite, potentially leading to weight gain.

Like SSRIs, SNRIs are often used to treat MDD. Similar to SSRIs, SNRIs prevent cells in your brain from reabsorbing certain neurotransmitters. This leaves more of them available to communicate with other cells.

In the case of SNRIs, the neurotransmitters affected are serotonin and norepinephrine.

SNRI antidepressants include:

  • desvenlafaxine (Khedezla, Pristiq)
  • duloxetine (Cymbalta)
  • levomilnacipran (Fetzima)
  • milnacipran (Savella)
  • venlafaxine (Effexor XR)

SNRIs are often used to treat depression, but they can also help with:

Common side effects

The more common side effects of SNRIs include:

  • headaches
  • nausea
  • insomnia
  • drowsiness
  • dry mouth
  • dizziness
  • loss of appetite
  • constipation
  • sexual problems such as low sex drive, erectile dysfunction, or ejaculation problems
  • weakness and fatigue
  • sweating

SNRIs can cause sexual side effects, but not as often as SSRIs. Some people who take SNRIs may also gain weight, but weight loss is more common.

In some cases, people taking SNRIs may notice increased blood pressure.

TCAs are an older group of antidepressants. Like SNRIs, they help to increase levels of norepinephrine and serotonin your brain. But they also decrease the effects of another neurotransmitter called acetylcholine.

This impact on acetylcholine increases the risk of certain side effects. As a result, TCAs are typically only used if SSRIs and SNRIs don’t work well for you.

Some common TCAs include:

In addition to treating depression, many TCAs are used for other conditions, including:

Common side effects

The more common side effects of TCAs include:

  • headaches
  • dry mouth
  • blurred vision
  • digestive issues, such as stomach upset, nausea, and constipation
  • dizziness
  • drowsiness
  • trouble sleeping
  • memory problems
  • fatigue
  • weight gain
  • sexual problems such as low sex drive, erectile dysfunction, or ejaculation problems
  • trouble urinating
  • fast heart rate
  • sweating

The side effects of TCAs are similar to those of SSRIs and SNRIs, but they tend to occur more frequently and can be more bothersome.

TCAs are also much more likely to cause certain side effects, including:

  • dry mouth
  • blurred vision
  • constipation
  • trouble urinating
  • weight gain
  • drowsiness

In rare cases, TCAs can also cause potentially dangerous heart-related side effects, such as:

  • low blood pressure when standing up
  • high blood pressure
  • abnormal heart rate or arrhythmia

Like TCAs, MAOIs are an older group of medications. Today, they’re not commonly used for depression, but your healthcare provider might suggest them if others aren’t offering relief.

MAOIs work by preventing your body from breaking down certain neurotransmitters. This causes an increase in your levels of serotonin, norepinephrine, and dopamine.

Some common MAOIs include:

  • isocarboxazid (Marplan)
  • phenelzine (Nardil)
  • tranylcypromine (Parnate)
  • selegiline (Eldepryl, Emsam)

In addition to depression, some MAOIs are used for other conditions. Phenelzine and tranylcypromine are sometimes used for panic disorder and social anxiety. Selegiline is used for Parkinson’s disease.

Common side effects

The more common side effects of MAOIs include:

  • low blood pressure
  • nausea
  • headaches
  • drowsiness
  • dizziness
  • dry mouth
  • weight gain
  • stomach pain
  • confusion
  • diarrhea
  • runny nose
  • sexual problems such as low sex drive, erectile dysfunction, or ejaculation problems

MAOIs are more likely to cause low blood pressure than other antidepressants. These medications can also interact with foods containing tyramine and cause dangerously high blood pressure.

SARIs are also known as serotonin modulators or phenylpiperazine antidepressants. They’re sometimes considered atypical antidepressants because they work differently. SARIs can help treat:

  • depression
  • anxiety
  • panic disorder

Like most other antidepressants, SARIs help to increase the amount of available serotonin — and sometimes other neurotransmitters — in your brain. But they do so in different ways from other antidepressants.

Some SARIs include:

Common side effects

The more common side effects of SARIs include:

  • drowsiness
  • dry mouth
  • headaches
  • dizziness
  • nausea
  • fatigue
  • vomiting
  • blurred vision
  • diarrhea
  • constipation
  • low blood pressure
  • confusion

Many people taking SARIs experience drowsiness or sleepiness. This makes them a potentially good option for people with insomnia, especially if they also have depression.

Some antidepressants simply don’t fit into any of the main group, usually because of the way they work. These are known as atypical antidepressants.

Bupropion (Wellbutrin)

Unlike most other antidepressants, bupropion doesn’t increase serotonin. Instead, it works to increase norepinephrine and dopamine. It’s sometimes classified as a norepinephrine-dopamine reuptake inhibitor.

In addition to being used for depression, bupropion is also used to help people quit smoking.

The more common side effects of bupropion include:

  • trouble sleeping
  • headaches
  • irritability or agitation
  • dry mouth
  • constipation
  • loss of appetite
  • weight loss
  • nausea
  • vomiting
  • sweating
  • dizziness
  • anxiety

Compared with other antidepressants, bupropion is less likely to cause weight gain. In fact, weight loss is a common side effect.

Bupropion is also less likely to cause sexual problems. As a result, it’s sometimes prescribed alongside other antidepressants to reduce their sexual side effects.

But it’s more likely than some other antidepressants to cause insomnia and anxiety. In rare cases, bupropion can cause seizures, especially when used in high doses.

Mirtazapine (Remeron)

Mirtazapine increases the effects of norepinephrine, serotonin, and dopamine in your brain in a different way than other antidepressants. It’s sometimes classified as a noradrenergic antagonist-specific serotonin antagonist.

The more common side effects of mirtazapine include:

  • drowsiness
  • dry mouth
  • increased appetite
  • weight gain
  • high cholesterol
  • constipation
  • weakness and fatigue
  • dizziness

Like SARIs, mirtazapine may cause sleepiness or drowsiness. As a result, mirtazapine may be used for those who have depression and trouble sleeping.

Mirtazapine can also cause increased appetite, making it more likely to cause weight gain than other antidepressants.

Vilazodone (Viibryd)

Vilazodone increases serotonin’s effects in the brain in ways both similar to and different from SSRIs. It’s sometimes called a serotonin partial agonist reuptake inhibitor.

The more common side effects of vilazodone include:

  • diarrhea
  • nausea
  • dizziness
  • dry mouth
  • trouble sleeping
  • vomiting

Vilazodone is less likely to cause weight gain than many other antidepressants, such as SSRIs and TCAs. Some people who take vilazodone have sexual problems, such as low sex drive or erectile dysfunction, but this seems to be less common with vilazodone compared to SSRIs and SNRIs.

Vortioxetine (Trintellix)

Vortioxetine is sometimes called a multimodal antidepressant. It functions somewhat like an SSRI, but has additional effects on serotonin levels.

The more common side effects of vortioxetine include:

  • sexual problems, such as orgasm or ejaculation problems
  • nausea
  • diarrhea
  • dizziness
  • dry mouth
  • constipation
  • vomiting

Vortioxetine is more likely to cause sexual side effects than many other antidepressants. But it’s less likely to cause weight gain.

The chart below is a general comparison of the some of the more common side effects associated with different antidepressants.

When using this chart, keep a few things in mind:

  • Everyone responds differently to antidepressants, so you may have additional side effects not listed here.
  • You likely won’t experience every single side effect associated with a particular antidepressant.
  • Some medications are more or less likely to cause certain side effects. Your healthcare provider can give you more information about common side effects linked to specific medications within each group.
  • Some side effects may become milder or disappear completely over time as your body gets used to the medication.
  • This chart only includes common side effects. Some antidepressants may have less common, more serious side effects, including increased suicidal thoughts.
[MOU1] Side effect SSRIs SNRIs TCAs MAOIs SARIs bupropion mirtazapine vilazodone vortioxetine
headache X X X X X X
diarrhea X X X X X X
dry mouth X X X X X X X X X
fatigue X X X X X X X
sweating X X X X
dizziness X X X X X X X X
blurred vision X X X
sexual issues X X X X X X
drowsiness X X X X X X X
insomnia X X X X X
weight gain X X X X X
weight loss X X X

Some antidepressants, including SSRIs, may cause an increase in suicidal thoughts or actions. This risk is higher in children, teenagers, and young adults. It’s also higher within the first few months of treatment or during dosage changes.

You and your family members, caregivers, and healthcare provider should watch for any new or sudden changes in your mood, behaviors, thoughts, or feelings. Call your healthcare provider right away if you notice any changes.

Suicide prevention

If you think someone is at immediate risk of self-harm or hurting another person:

  • Call 911 or your local emergency number.
  • Stay with the person until help arrives.
  • Remove any guns, knives, medications, or other things that may cause harm.
  • Listen, but don’t judge, argue, threaten, or yell.

If you or someone you know is considering suicide, get help from a crisis or suicide prevention hotline. Try the National Suicide Prevention Lifeline at 800-273-8255.

There are many types of antidepressants. Each comes with its own list of potential side effects. When choosing and trying an antidepressant, it’s important to work closely with your healthcare provider, especially as you get used to a medication’s side effects.

Before starting any new medication, let your healthcare provider know about any other medications you take, including over-the-counter drugs and herbal supplements, such as St. John’s wort. If you drink alcohol, make sure to also ask about any potential interactions it might have with your medication.

In addition to side effects, antidepressants can also cause allergic reactions in some people. Seek immediate medical treatment if you notice any symptoms of a severe allergic reaction, such as difficulty breathing or swelling in your face, tongue, or throat.