What are antidepressants?
Antidepressant medicines are medicines used to treat depression, anxiety and related conditions, such as eating disorders, obsessive-compulsive disorder and post-traumatic stress disorder.
These medicines affect a number of chemicals in the brain that influence mood and anxiety, such as serotonin, noradrenaline and dopamine.
Medication is just one way that depression and anxiety are treated. Other treatments may also be needed, such as psychological treatments (talking therapy) or lifestyle changes.
What are the different types of antidepressants?
There are many different types of antidepressants. They can be grouped according to how they work in the body. Within each group, there are several different medicines that work in a similar way.
- SSRIs, or selective serotonin reuptake inhibitors. They are not necessarily more effective than others, but they tend to have fewer side effects. They include citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, sertraline
- SNRIs, or serotonin and noradrenaline reuptake inhibitors, including duloxetine, venlafaxine, desvenlafaxine
- Serotonin modulator, including vortioxetine
- Noradrenaline reuptake inhibitors such as reboxetine
- TCAs (Tricyclic antidepressants), including amitriptyline, nortriptyline, clomipramine, dothiepin, doxepin, imiprimine, trimipramine
- RIMAs (Reversible inhibitors of monoamine oxidase A), such as moclobemide
- Tetracyclic antidepressants such as mianserin
- Tetracyclic analogues of mianserin such as mirtazapine
- MAOIs (monoamine oxidase inhibitors), including phenelzine and tranylcypromine
- Melatonergic antidepressants such as agomelatine
Your doctor will prescribe an antidepressant based on your symptoms or disorder. People respond differently to different antidepressants, so it may be necessary for a doctor to trial more than one antidepressant to find one that works well for you with few side-effects.
NPS MedicineWise has a detailed list of antidepressants, which can be searched by active ingredient as well as by brand name.
Do I need antidepressants?
As with many other medications, there are benefits and risks to taking antidepressants.
They are often effective for moderate to severe depression. They can help to improve mood and increase motivation for people who may have lost interest in activities they once enjoyed. They can also help improve sleep, thinking and concentration.
Antidepressants might also help people with anxiety-related disorders like generalised anxiety disorder (GAD), eating disorders, obsessive-compulsive disorder (OCD) and post-traumatic stress disorder (PTSD).
However, antidepressants are not particularly effective for mild depression. Lifestyle changes and psychological treatments work better for mild depression.
The decision to start an antidepressant should be made only in consultation with a doctor.
Other medicines may also be needed as well as or instead of antidepressants. These include anti-anxiety medication or sleeping tablets.
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What side effects do antidepressants have?
Like all medicines, antidepressants may have side effects. For most people, the side effects are not bad enough that they need to stop taking the medication.
Different people may experience different side effects, so it’s important to talk to your doctor about your personal situation. Some people experience no side effects at all.
Side effects differ between antidepressants. Some side effects may include:
- weight gain
- diarrhoea or constipation
- a dry mouth
- difficulty sleeping
- sexual side effects
- dizziness or blurred vision
If you experience a side effect from an antidepressant, it’s important to let your doctor know. It may be possible to reduce side effects by changing the dose or the time of day the medicine is taken. Some people may need to switch to another antidepressant due to side effects.
Many antidepressants can interact with other medicines. Anybody taking antidepressants needs to make sure their doctor and pharmacist know what other medicines they are taking, including any complementary or alternative therapies.
There are links between antidepressants and suicidal thoughts and behaviours in young people. But sometimes the need for antidepressants outweighs the risk of taking the medicines. The decision to prescribe antidepressants for young people is one that should be taken with great care.
How long do antidepressants take to work?
If you have depression, you may start to feel better 2 to 4 weeks after starting an antidepressant but it can take up to 6 to 8 weeks to feel the full effect. Many side effects go away after a few weeks, so allow time.
If you have an anxiety disorder, it may take 4 to 6 weeks before you start feeling better and it may take up to 12 weeks to feel the full effect of the antidepressant.
In some people, antidepressants are not effective, no matter how long they are taken for.
Anybody who takes antidepressants should see their doctor regularly, especially in the first few weeks.
How long should I be on antidepressants?
Most people are advised to keep taking their antidepressant for at least 6 to 12 months after they start to feel better, to reduce the risk of symptoms returning. It’s important to discuss with your doctor about the best time to stop an antidepressant.
In some people, ongoing antidepressant treatment is recommended to maintain long-term control over their illness.
Other things to be aware of
To take your medication safely:
- Tell your doctor if you are taking other medications.
- Ask your doctor if your antidepressant is affected by food.
- Store your antidepressants in a box, away from children in a cool, dry place.
- Don’t share your antidepressants with other people.
- Take the recommended dose.
- Continue to take medication even when you are feeling better until you have discussed stopping with your doctor.
- Cut down or stop alcohol consumption, as this can reduce the benefits of antidepressants and in some cases can be very dangerous.
How do I stop taking antidepressants?
You should always stop taking antidepressants slowly, and under a doctor’s supervision. Stopping most antidepressants suddenly can result in unpleasant symptoms such as dizziness, nausea or feeling edgy.
It’s important to work closely with a doctor to lower the dose, stop or switch antidepressant medicines.
Are antidepressants addictive?
Antidepressants are not addictive, however it’s important to talk to a doctor before stopping them to avoid unpleasant side effects.
Alternative treatments for depression and anxiety
Some people get better with psychological therapy alone. Others find it best to use a combination of antidepressants and psychological therapy.
There are many different psychological therapies. The most common is cognitive behavioural therapy. This therapy aims to identify and change your negative thoughts.
Other types of therapy aim to get you to accept your thoughts and environment in a non-judgemental way, or help you change patterns of behaviour that are not helpful.
Talk to your doctor about options for treatment. You might be eligible for a mental health care plan, which reduces the cost of treatment.
There are other things that help your anxiety and depression.
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Last reviewed: October 2021