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How long does it take antidepressants to work?

You likely won’t feel better right away, but there are some things you can do to make the waiting period easier

If you’ve been prescribed an antidepressant, it’s probably because you’ve been experiencing levels of anxiety or depression that are interfering with your daily function or quality of life. This can be scary, frustrating, and exhausting, so chances are that once you begin taking an antidepressant, you want it to start working right away.

Unfortunately, there is a waiting period when you start taking an antidepressant: While some take less time than others to work, you won’t be feeling the full effects of your medication for a few weeks, at least. Here’s what you can expect when you start taking an antidepressant—from what side effects you might experience to how long you can expect to wait until you’re feeling like yourself again.

How do antidepressants work?

Antidepressants are prescription drugs that cause changes in your brain’s neurotransmitters, i.e., the chemicals that send messages within your brain and may also strengthen the neuron connections in your brain. Ultimately, these chemical changes can improve your overall mood. Antidepressants may be prescribed to reduce symptoms of depression, anxiety, obsessive-compulsive disorder (OCD), depression associated with bipolar disorder, or panic disorder, among other conditions.

There are many different types of antidepressants, but the most common treatment options are:

Antidepressant medication is most often prescribed in tablet form; it depends on the specific drug and condition treated. While the dosage varies by medication, healthcare providers generally prescribe a lower dose to start and slowly increasing the dose if needed. It is often recommended that antidepressant treatment is paired with psychotherapy for maximum benefits. 

The goal of taking an antidepressant is to feel more like your usual self again. They won’t make you feel artificially happy, but they can help you recover some of the function you may have lost in your life because of your anxiety or depression. It’s also important, though, to continue taking care of yourself in other ways once you begin antidepressants, like going to regular therapy, managing stress, and getting enough exercise and quality sleep.

How long does it take for antidepressants to work?

Most conventional antidepressants take several weeks to work. While you might feel some improvement during the first two weeks, it can take from four to eight weeks to feel the full benefits of these drugs, says psychiatrist Sid Khurana, MD, the medical director for Nevada Mental Health. 

That doesn’t mean you won’t feel anything when you start taking an antidepressant, such as Prozac (fluoxetine) and Zoloft (sertraline); Dr. Khurana says the side effects of these drugs often appear earlier than the intended therapeutic effects, so you may notice some mild symptoms like dizziness or nausea within a few days of taking your first pill.

How do I know if my antidepressant is working?

It’s a bit of a waiting game as far as figuring out whether your antidepressant is working the way you expected. Some antidepressants don’t work well for some people, while others only need their dosage adjusted until they find the right amount. This is a step you can’t rush, however, even though it can be frustrating.

“The rule is to start low and go slow unless the benefits of going fast outweigh the risks of side effects,” Dr. Khurana says. “Typically, dosage adjustments are made every two to four weeks, depending upon the symptom severity and the choice of antidepressant.”

Your prescribing provider will work with you to determine whether your dosage is strong enough or needs to be increased based on regular check-ins. It’s important to be honest with your healthcare provider about how you’ve been feeling, including the positive and negative side effects you’ve experienced.

If you’re having some unpleasant side effects to starting a new antidepressant, there are some ways to ease the transition, says Bruce Bassi, MD, an addiction psychiatrist at TelepsychHealth. “The adage is ‘the treatment is time,’ as the side effects—especially the gastrointestinal ones—tend to get better [the longer you’re on the drug],” Dr. Bassi explains. 

In the meantime, he says there are some common tricks you can employ to make the side effects more tolerable until they go away, such as timing the medication to take it with food or asking your provider for a low dose of another medication to temporarily treat side effects (an anti-nausea drug, for example).

If you have a handle on side effects but are impatiently waiting to feel the therapeutic benefits of your antidepressant, Dr. Khurana says it’s important to incorporate other self-care strategies into your routine in the interim. This might include:

  • Eating healthy, nutritious meals
  • Getting regular exercise
  • Getting quality sleep (and practicing good sleep hygiene)
  • Attending therapy sessions or support group meetings
  • Practicing meditation or mindfulness 

Exercise, in particular, is beneficial: “Exercise has a very strong antidepressant effect, and it is extremely important to incorporate exercise to boost [that],” Dr. Khurana says.

What are the side effects of antidepressants?

There are several common side effects of antidepressants, though most people won’t experience all of them, and they tend to be mild. The most common side effects include:

  • Gastrointestinal upset, especially nausea 
  • Increased appetite or weight gain
  • Dry mouth
  • Drowsiness or fatigue (or on the other hand, trouble sleeping)
  • Dizziness and headache
  • Constipation
  • An increase in anxiety or agitation
  • Lower libido

The likelihood of having side effects depends partly on your body chemistry, on any other health conditions you may be treating, and on the medication itself. In general, Dr. Bassi says:

  • SSRIs are more likely to cause GI and sexual side effects.
  • TCAs that are strongly anticholinergic are more likely to cause dry mouth, constipation, and fogginess.
  • Medications with a strong antihistamine component, such as Paxil, can lead to sedation and weight gain.

Most of these side effects will be temporary, but it’s possible that even temporary side effects may be too intense for you to continue taking the medication. If you feel this way, contact your prescribing provider as soon as possible; don’t discontinue taking the medication without consulting your provider. Your provider may decide it’s best to switch your medication, or they may suggest ways for you to cope with the side effects until they resolve.

Some people also notice certain emotional side effects when they begin taking an antidepressant; they feel numb as if their senses have been dulled. This is often referred to as “emotional blunting,” and can happen when your dose is too high. Talk to your provider if you’re experiencing feelings of numbness after starting an antidepressant.

Finally, some people may experience an increase in feelings of anxiety or restlessness, which can be especially frustrating if you’re taking the drug to treat an anxiety disorder. This is called activation syndrome—essentially a hyperarousal of the nervous system in response to the drug, and while it’s temporary, can be distressing.

If you experience any of the following side effects after beginning antidepressants, call your provider or seek emergency care immediately, as they could be signs of serious adverse effects like serotonin syndrome or overdose: 

  • Suicidal thoughts or ideation
  • Vomiting 
  • Sweating
  • Increased heart rate
  • Increased blood pressure
  • Confusion 
  • Seizures 

Length of antidepressant treatment

Many people are reluctant to start antidepressants because they are afraid they will become dependent on them or will need to take them for the rest of their lives. But this isn’t always true; while some people remain on antidepressants for long periods of time, others discontinue use after a marked period of improvement. 

Dr. Bassi says he describes antidepressants as “helping you get to a better place in life.” If there were other precipitating factors that contributed to your depression, he explains, like relationship issues, problems at work, or difficulty sleeping, resolving those issues in combination with antidepressant use can improve your overall situation. 

How long might this take? It largely depends on you and your unique situation, but Dr. Bassi says he usually recommends staying on antidepressants for six to 12 months after feeling better, which aligns with the current national guidelines. You shouldn’t expect to discontinue taking antidepressants the moment you feel better because that can cause a relapse, but you should keep the line of communication open with your healthcare team so you can decide together if, when, and how to try gradually weaning off the medication.

Of course, there are people who will need to continue some kind of antidepressant treatment indefinitely. This can include people with severe anxiety disorders and people with major depressive disorder. But try not to allow your concerns over the length of treatment prevent you from seeking the help you need and deserve. Many people take antidepressants for long periods of time.

The bottom line

When you first begin taking an antidepressant, you should expect to notice some minor improvements after one to two weeks and feel the full effects within two or three months. If you don’t feel any improvement after several weeks of treatment, you should check in with your provider.

While you wait for your medication to work, you may have some mild side effects like nausea, dizziness, and weight gain. If at any point your side effects are not mild, or if they’re impeding your ability to function, talk to your provider right away: They may be able to make an adjustment to the type or dose of your medication or share tips to make the transition period smoother. 

Suicidal thoughts while taking antidepressants are a rare but serious side effect; if you are experiencing severe depression, any thoughts of self-harm, or having suicidal ideations, call the National Suicide Prevention Lifeline at 988.