Most antidepressants take time, usually about 4 to 8 weeks, to show their full effect, according to the National Institute of Mental Health. Problems with sleep, appetite and concentration often improve before mood lifts, and NIMH's STAR*D summary notes that full benefits may not be realized until 10 or 12 weeks. A slow start does not by itself mean the medication has failed.
Part of our guide: A Patient’s Guide to Psychiatric Medication
It helps to keep two things separate: how long the medication needs, and how closely you should be watched while it builds. The first is measured in weeks. The second starts on day one, because the early period is also when side effects and safety concerns need the most attention.
If you are thinking about suicide or self-harm, or are worried about someone else: call or text 988 (988 Suicide & Crisis Lifeline), call 911 or go to the nearest ER.
What the research shows about timing
One of the largest real-world depression studies is STAR*D, funded by the National Institute of Mental Health. People with depression took one antidepressant, citalopram, with regular symptom measurement. According to the NIMH summary of the study, it took an average of six weeks to improve enough to count as a response and nearly seven weeks to reach remission, meaning they became symptom-free or close to it.
Timing also varied. A 2008 review of STAR*D for primary care noted that a substantial share of people who reached remission did so between weeks 6 and 12. Two limits apply here. Everyone in that first stage took the same medication, and NIMH notes that the study's careful measurement may have produced higher remission rates than expected. These averages describe groups and cannot predict one person's course.
A rough timeline
This sketch is general, and your prescriber's plan for you comes first.
| Period | What is often happening | What to focus on |
|---|---|---|
| First days to 2 weeks | The medication is getting started. Side effects may appear before benefits do. | Report side effects and any mood or behavior changes right away. It is too early to judge the benefit, but do not wait to report a problem. |
| Weeks 2 to 4 | Some people see early changes. Others see nothing yet, and both can be normal. | Keep taking it as prescribed unless your prescriber tells you otherwise, keep follow-up visits and call about anything worrying. |
| Weeks 4 to 8 | The range in which NIMH says antidepressants usually work. | Review progress with your prescriber using specifics. |
| Beyond 8 weeks | Some people are still improving. Others have reached a plateau. | Decide together whether to continue, adjust or change the plan. |
Why the first weeks need extra attention
Antidepressants carry an FDA boxed warning, the agency's most prominent type of warning. The sertraline (Zoloft) label states that antidepressants "increased the risk of suicidal thoughts and behavior in pediatric and young adult patients" in short-term studies, and tells prescribers to closely monitor all antidepressant-treated patients for worsening and for new suicidal thoughts and behaviors. The label says this monitoring matters most during the first few months of treatment and at times of dose changes.
The same label's Medication Guide tells patients and families to call a healthcare provider right away about these changes, especially if they are new, worse or worrying:
- Thoughts about suicide or dying, or suicide attempts
- New or worse depression, anxiety or panic attacks
- Feeling agitated, restless, angry or irritable
- Trouble sleeping
- Acting aggressive or violent, or acting on dangerous impulses
- An increase in activity or talking more than what is normal for you
- Other unusual changes in behavior or mood
Antidepressants can also bring on mania or hypomania in people with bipolar disorder. The label tells prescribers to screen for a personal or family history of bipolar disorder before treatment starts, so mention any such history at your first visit. If you feel unusually energized, need far less sleep or feel your thoughts racing after starting, call your prescriber promptly. For more on how these conditions differ, see this article on bipolar disorder vs mood swings.
Teens and young adults
The Medication Guide says antidepressants may increase suicidal thoughts or actions in some people 24 years of age and younger. That risk is the reason parents and caregivers are asked to take an active part in the early weeks. If you are a parent, agree with your teen on how you will check in, learn the warning signs listed above and know how to reach the prescriber. This does not mean a young person should never take an antidepressant. It means the decision should weigh the risks of treatment against the risks of untreated depression, with close follow-up either way. This article on therapy vs medication for children and teens covers that decision in more detail.
What can change how quickly it seems to work
Several ordinary factors affect what you notice and when:
- Missed doses. Tell your prescriber honestly about gaps. That information changes how the results are read.
- Which symptoms you are watching. Ask someone close to you what they have noticed, since their view can add to your own.
- Other conditions and substances. Other health problems, other medications and alcohol can all affect the picture. This article on alcohol and cannabis with psychiatric medication covers this in more depth.
- The diagnosis itself. If improvement stalls, a good next step is often to check whether the working diagnosis still fits.
How to track progress between visits
Memory is a poor measure when you are depressed. A short weekly note gives your prescriber better information than trying to recall a whole month during an appointment. Try rating or noting:
- Sleep, appetite and energy
- Whether you did things you had been avoiding, such as work tasks or seeing friends
- Any side effects, when they started and whether they are fading
- Missed doses
- Any dark thoughts, which you should report right away instead of saving for the next visit
NIMH also advises that giving a medication a chance to work is important before deciding whether it is right for you. A log makes that decision easier and more honest. Therapy can run alongside medication during this time. This article on medication vs therapy for depression compares the options.
Questions to ask when you start
- When should I expect to notice a change, and what change should I look for first?
- When is my first follow-up, and who do I call if something worries me before then?
- Which side effects are likely to fade, and which ones need a call right away?
- How will we decide whether this is working?
- If it is not helping by a certain point, what would we consider next?
What happens if it has not helped after several weeks
Many people do not get full relief from their first antidepressant. In STAR*D's first stage, about one-third of participants reached remission, by NIMH's summary, and the 2008 review gives 28%. That is a common reason to adjust the plan, and it says nothing about you or your effort.
Options a prescriber may discuss include adjusting the current medication, adding another treatment, adding therapy, or switching to a different antidepressant. NIMH describes treatment-resistant depression as when a person does not get better after trying at least two antidepressants. For that situation, other treatments exist, including Spravato, which is FDA-approved for adults with treatment-resistant depression and is self-administered under supervision in a certified setting. It carries its own FDA boxed warning covering sedation, dissociation, respiratory depression, abuse and misuse, and suicidal thoughts and behaviors.
If you are feeling better, the same caution applies in reverse. NIMH says people should not stop taking a prescribed medication even when feeling better without the help of a healthcare provider, because stopping too soon may cause unpleasant or harmful side effects. Make any change only with your prescriber.
If you would like help reviewing your timeline or your options, medication management at Mind Body Seven is one place to start. You can request a consultation, and the intake team confirms fit, scheduling and costs.
FAQs
Can you feel an antidepressant working in the first week?
Some people report small shifts early, but early changes are not a reliable guide to where things will end up. Side effects can also appear first. Share what you notice at your follow-up visit.
Do side effects mean the medication is working?
No. Side effects and benefits are separate. NIMH says side effects of SSRIs and other antidepressants are generally mild and tend to go away with time, but tell your prescriber about any that bother you, and call right away about sudden mood or behavior changes.
What if an antidepressant works and then seems to stop?
A return of symptoms has several possible causes, including life stress, sleep problems, other medications or a change in the illness itself. Raise it with your prescriber instead of changing the dose yourself. This article on when a medication doesn't work goes through what a review can include.
Do antidepressants for anxiety take the same amount of time?
NIMH notes that many medications used for depression, including SSRIs and SNRIs, may also be used to treat anxiety. Ask your prescriber what timeline to expect for your condition and medication, since this can differ.
