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Overview of antidepressants

Antidepressants are medicines used to help treat certain mental illnesses. These include depression, anxiety and panic attacks.

They can also help with some cases of eating disorder and chronic (persistent) pain. Also, obsessive compulsive disorder (OCD) and post-traumatic stress disorder (PTSD).

Talking therapies are often used alongside antidepressant medication.

Health professionals believe that antidepressants work by increasing the activity of neurotransmitters. Neurotransmitters are chemicals in our brains. Certain neurotransmitters, such as serotonin and noradrenaline, affect mood and emotion.

Types of Antidepressants

There are several kinds of antidepressants.

Selective serotonin reuptake inhibitors (SSRIs) are usually the first choice. This is because they often work well and are safe. They also do not usually cause unwanted symptoms (side effects). These include citalopram, escitalopram, fluoxetine, paroxetine and sertraline.

Venlafaxine works in a similar way to the SSRIs but also has other effects. You might need to try it if SSRIs do not help.

Less used antidepressants include:

Some people respond better to one antidepressant medicine than another. You may need to try different ones before finding the one that works best for you.

Most people take 1 antidepressant at a time. Some people may need to use 2 antidepressants in combination.

Things to consider when choosing which antidepressant to use include:

How soon antidepressants work

Most antidepressants start helping within 2 weeks of starting to take them. It usually takes between 4 and 6 weeks before you get the full effect. If you do not feel any better after 2 to 4 weeks, tell your health professional. You may need to increase your dose or change to another antidepressant.

Side effects from antidepressants


Rarely, antidepressants can make you more anxious and restless in the first 2 weeks of taking them. You can even have feelings of self-harm or suicidal thoughts. If this happens, talk to your healthcare provider. Or contact a mental health crisis support line.

Antidepressants can cause unwanted symptoms known as side effects. Side effects are usually mild and do not last long. Some people experience no side effects.

You may have minor side effects when you start taking an antidepressant. If so, try staying on the medicine for a few weeks. Minor side effects often go away after your body gets used to the new medicine.

If the side effects do not go away or are worrying you, tell your healthcare provider. They may have suggestions for how to reduce or manage your side effects.

Common side effects of antidepressants include nausea and diarrhoea. They also include sleep problems, sexual problems, sweating and dry mouth.

Stopping antidepressants

There is no set time for how long you should take antidepressants. Most people will need to take them for at least 6 to 12 months. This can help stop your symptoms coming back.

Antidepressants are not addictive. But if you stop taking them suddenly, you may get some symptoms. This is known as antidepressant withdrawal or discontinuation syndrome.

You need to decrease most antidepressants slowly. You may need to drop the dose by small amounts each week, or every two weeks or every month.

You should talk to your healthcare provider before stopping your medication. They will help you make a plan for how you are going to do this.

For more information, see Stopping antidepressants.

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Written by HealthInfo clinical advisers. Page created December 2023.


Page reference: 1292820

Review key: HIMMH-215644