Antidepressants can improve symptoms of depression. But, are the results immediate?

If you’re thinking about starting a new antidepressant or you just got a prescription from a health professional, you may have questions, including how long the drug will take to work.

The answer to this question depends on many factors, including:

  • the severity of your symptoms
  • whether you’re going to therapy
  • the type of medication you’re taking

You may have taken the courageous step to seek professional help for depression. Your symptoms can be managed, and antidepressants have helped many people.

Most antidepressants don’t work right away. Or at least, you may not notice the changes right away.

Many of them, such as selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs), generally take about 2 to 8 weeks to work.

However, a newer class of antidepressants known as N-methyl-d-aspartate (NMDA) receptor blockers may work faster in some cases. You may feel their effect on your mood within hours or days of receiving your first dose.

Why is that?

Different types of antidepressants work on different chemicals in your brain called neurotransmitters. Neurotransmitters help transfer messages from nerve cells to other cells in your brain and body.

Examples of neurotransmitters commonly affected by antidepressants include:

Newer antidepressants work on other types of neurotransmitters, such as:

This makes a difference in terms of how long antidepressants take to work. Here’s why.


SSRIs work by preventing serotonin from being taken up by nerve cells, so more serotonin is available to send messages. SNRIs do the same with serotonin but also norepinephrine.

Commonly prescribed SSRIs include:

Examples of commonly used SNRIs include:

Scientists believe that having more neurotransmitters freely available in your brain helps you make more positive interpretations of your experiences.

Over time, your brain makes new connections associated with these positive interpretations.

As new nerve pathways are formed, your mood and behaviors improve.

But, it may take a few weeks for you to experience these changes. Even though the antidepressant is working right away, it takes some time to manifest in your mood and behaviors.

NMDA receptor blockers

Esketamine (Spravato) is a new antidepressant that belongs to the class of drugs called NMDA receptor blockers.

Esketamine is used along with psychotherapy to treat depression symptoms when other medications haven’t worked.

Esketamine works by blocking NMDA receptors in your brain, which stimulate your brain cells to release more of the neurotransmitter glutamate.

Glutamate is the most abundant and the primary excitatory neurotransmitter in your brain. Excitatory neurotransmitters prompt your cells to take action.

Because not everyone experiences depression in the same way, the signs that an antidepressant is working may also vary.

Some common indicators that your antidepressant medication has kicked in may include any of the following:

  • Feelings of guilt may decrease.
  • You may feel more hopeful about yourself and life.
  • Suicidal thoughts and behaviors may lessen.
  • You may have more energy and motivation to do things.
  • You may once again want to do activities that you used to enjoy before.
  • You may sleep better.
  • You may start feeling like you used to.
  • Anxiety symptoms may also improve.
  • Your appetite may improve.

Getting used to a new antidepressant takes some time.

When you first start taking an antidepressant, you may notice side effects before you feel relief during the first few weeks.

It’s not unusual to experience any of the following side effects during the first month of your antidepressant treatment:

  • dizziness
  • dry mouth
  • headache
  • nausea
  • sleep disturbances

These side effects should decrease with time, and you should begin to feel your mood and symptoms improve.

If you don’t notice improvement after about 8 weeks, try talking with your health professional. They may decide that a change in dosage may help.

It’s highly recommended that you don’t adjust your dosage or stop taking the medication without consulting with a professional first.

It’s understandable to want your antidepressant to start working right away.

You may feel discouraged or frustrated with the side effects you initially feel. But, it’s often a good idea to be persistent.

If you stick to your prescribed treatment, you’ll notice that the side effects will likely diminish, and your symptoms may improve.

In fact, each day that you continue to take your antidepressant, your brain is making new connections to help you create pathways to more positive thoughts and behaviors.

It’s important to remember that everyone experiences their depression symptoms differently and has different reactions to medications.

Consider talking with your mental health professional about any concerns you may have about your depression medication and side effects. For example, if you can take antidepressants when breastfeeding or if you can drink when taking medication. The professional has the experience needed to guide you and explain any reactions you may be having.

These are some examples of questions you may want to discuss with your health team:

  • Can I stop taking my antidepressant if my side effects don’t improve?
  • If this antidepressant doesn’t work for me, will another one work better?
  • Can I take my new antidepressant with my other medications?
  • What should I do if my depression symptoms get worse?
  • Will I eventually get off the antidepressant if my depression symptoms improve?
  • What precautions should I take when taking my antidepressants?
  • Do I need to do something else besides taking antidepressants?
  • What happens if I forget to take my medication?

Antidepressants can be effective in treating symptoms of depression. How long they take to work may depend on many factors.

Most antidepressants typically take up to 8 weeks to work. However, each person reacts differently to medications.

The time it takes for your antidepressant to begin working will vary based on how your body reacts to the medication and what your symptoms are.

Although you may not feel the effects right away, your brain is hard at work making new pathways and connections as soon as you begin taking your antidepressant.

Professional and social support is also important during this time.

Symptoms of depression can be managed, and considering professional treatment is an important step toward improving how you feel.