Key takeaways:
Antidepressants usually take about 4 to 8 weeks to reach their full effects. Side effects, on the other hand, can start right away and then improve over time. So it’s best to wait at least 4 weeks to determine if an antidepressant is a good fit for you.
How long an antidepressant takes to work can vary based on your body chemistry and what you’re taking it for. It may take some trial and error to find the one that works best for you.
Keep in close contact with your healthcare team while taking an antidepressant. They can make adjustments to help with side effects or effectiveness. If you notice unusual changes in your mood or behavior, such as suicidal thoughts, seek medical help right away.
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Taking care of your mental health is just as important as taking care of your body. This can mean different things for different people, such as eating nutritious foods, getting enough sleep, or spending time with loved ones. But if you're feeling depressed and lifestyle changes aren’t helping, an antidepressant might be a helpful option to consider.
Antidepressants can help with depression symptoms. But knowing what to expect — such as how long antidepressants take to work — can help you get the most from your treatment. Here, we’ll take a closer look at the average timeline for antidepressant effects, and why it can be different for everyone.
How long does it take antidepressants to work?
The American Psychiatric Association (APA) states that it can take 4 to 8 weeks for an antidepressant to be fully effective. For example, one clinical trial looked at almost 3,000 people taking citalopram (Celexa) for depression. Most people who experienced a significant improvement in depression symptoms only did so after 6 to 8 weeks of treatment.
Keep in mind that you may start to feel relief sooner than this — especially if you’re taking an antidepressant for other conditions, such as anxiety or premenstrual dysphoric disorder (PMDD). Anxiety symptoms typically improve within 2 to 6 weeks of starting an antidepressant.
That being said, everyone’s brain chemistry is unique. So while these ranges are a good guideline, it’s possible that an antidepressant may work faster or take longer to kick in for you. This is why it’s helpful to talk to your healthcare team regularly about how you’re feeling. They can make adjustments that are specific to your needs.
Why do antidepressants take so long to work?
Antidepressants work by raising the levels of certain chemicals — mainly serotonin, dopamine, and/or norepinephrine — in the brain. These chemicals, called neurotransmitters, help regulate your mood and stress levels. Experts believe that low neurotransmitter levels contribute to depression and other mental health conditions.
But this shift in brain chemicals doesn’t typically change your mood or behaviors right away. Your body needs time to adapt before you start feeling the benefits. Researchers estimate that it takes 3 to 5 weeks for the brain to form new connections and improve how it processes information after starting an antidepressant.
Some research also suggests that antidepressants also help reduce negative thought patterns. This can lead to a more positive outlook over time.
How do you know if your antidepressant is working?
You’ll know your antidepressant is working if you experience positive changes in your mood and activity level. You may feel like you have more energy to do daily tasks or find more joy from events in your life.
How to know your antidepressant is working: Here are some signs to look for to help you determine if your antidepressant is making a difference.
Do antidepressants work for anxiety? Antidepressants are a first-choice treatment for many types of health conditions — not just depression. Find out more about antidepressants for anxiety.
Are you dealing with treatment-resistant depression? If antidepressants haven’t worked for you, you could have treatment-resistant depression. Learn more about your options for treatment.
Antidepressants work best when you combine them with other good self-care practices. This can be difficult, but do your best to get enough sleep, eat well, and do some sort of physical activity on a regular basis. Your prescriber may also recommend working with a counselor or therapist to optimize the effects of your medication.
Good to know: Antidepressants aren’t one-size-fits-all. It may take a few tries to find the one that works best for your needs. Don’t hesitate to let your prescriber know if you aren’t noticing a change in your mood or behavior after 4 to 6 weeks of treatment.
Quiz: Is your antidepressant working?
Do you need to take an antidepressant forever?
It depends. The APA recommends taking an antidepressant for at least 4 to 9 months once your symptoms improve, referred to as remission.
It’s estimated that up to 75% of people stop taking antidepressants within 6 months of starting. But there’s a high relapse rate for people who stop taking antidepressants. This means it's common for people to become depressed again after they stop taking their medication. If you stop taking an antidepressant and your symptoms return, it may be a sign that long-term treatment could benefit you.
A large review of studies showed that continuing your antidepressant for at least 6 months after remission helps lower the chance that your depression symptoms will return. Research also suggests that taking an antidepressant for at least 10 to 12 months may help reduce the risk of relapse.
If your prescriber recommends an antidepressant, talk to them about how long they expect you to take it. Together, you can decide what length of treatment is right for you. If you decide to stop the medication, your prescriber can help you do so safely. Stopping an antidepressant abruptly on your own can cause unwanted side effects.
What are some common antidepressant side effects?
While you’re waiting to feel the positive effects of your antidepressant, you may notice you’re feeling something else: side effects. The good news is that many antidepressant side effects go away over time as your body adjusts to the medication. So giving your antidepressant several weeks to start working also allows time for side effects to resolve.
The specific side effects you may experience will depend on what type of antidepressant you’re taking.
Common side effects of selective serotonin reuptake inhibitors (SSRIs) and serotonin and norepinephrine reuptake inhibitors (SNRIs) include:
Nausea and upset stomach
Headache
Diarrhea or constipation
Problems with sleep
Low sex drive
Common tricyclic antidepressant (TCA) side effects include:
Dry mouth
Dizziness
Constipation
Common bupropion (Wellbutrin SR, Wellbutrin XL) side effects include:
Dry mouth
Headache
Upset stomach
Insomnia
Common mirtazapine (Remeron) side effects include:
Sleepiness
Dry mouth
Greater appetite and weight gain
Constipation
Contact your prescriber if you experience any side effects that worry you. This includes any unusual changes in your mood or behavior.
Keep in mind that children, teens, and young adults may be more likely to experience suicidal thoughts or actions when starting a new antidepressant or changing doses. Seek emergency care or call the National Suicide Prevention Lifeline by dialing or texting 988 if this side effect occurs.
When should you talk to your prescriber if you’re concerned about whether your antidepressant is working?
Reach out to your prescriber right away if you notice any of the following issues after starting an antidepressant:
Side effects are negatively impacting your daily life
Worsening mental health symptoms
Unusual changes in your thoughts or behavior
Suicidal thoughts
Otherwise, it’s a good idea to check in with your healthcare team after about 4 weeks of taking a new antidepressant. They may check if your symptoms have improved by using a questionnaire designed to track your symptoms. If you don’t feel any symptom improvement, or if you’re having significant side effects, your prescriber may decide to change your dose or switch you to a different antidepressant.
Frequently asked questions
Some antidepressant side effects, such as nausea or loss of appetite, resolve within 2 to 6 weeks after starting treatment. But others, such as sexual side effects, may continue for as long as you’re taking the medication. The good news is that many side effects can be managed with a dosage adjustment or additional medication. So don’t hesitate to discuss any concerning side effects with your healthcare team.
It isn’t common, but antidepressants can sometimes stop working as well over time. This is sometimes referred to as breakthrough depression. Experts aren’t exactly sure why this happens. Though some possible causes include changes in brain chemistry or life changes that are making your symptoms worse. Missing doses can also make antidepressants less effective. If your symptoms return while taking an antidepressant, check in with your prescriber. They can help you figure out the cause(s) and best next steps.
Some antidepressant side effects, such as nausea or loss of appetite, resolve within 2 to 6 weeks after starting treatment. But others, such as sexual side effects, may continue for as long as you’re taking the medication. The good news is that many side effects can be managed with a dosage adjustment or additional medication. So don’t hesitate to discuss any concerning side effects with your healthcare team.
It isn’t common, but antidepressants can sometimes stop working as well over time. This is sometimes referred to as breakthrough depression. Experts aren’t exactly sure why this happens. Though some possible causes include changes in brain chemistry or life changes that are making your symptoms worse. Missing doses can also make antidepressants less effective. If your symptoms return while taking an antidepressant, check in with your prescriber. They can help you figure out the cause(s) and best next steps.
The bottom line
Antidepressants can be a helpful part of treating depression, but they don’t work overnight. It can take 4 to 8 weeks for antidepressants to reach their full effects. Side effects, on the other hand, typically start right away and then improve over time. It’s best to stick with an antidepressant for at least 4 weeks before deciding whether it’s a good fit for you.
Keep in mind that how long an antidepressant takes to work can vary based on your body chemistry and what you’re taking it for. Keep in close contact with your healthcare team to find the medication and treatment plan that works best for you. If you ever feel worse or have side effects that bother you, don’t wait — talk to your prescriber right away.
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References
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