Antidepressant medication can effectively treat moderate to severe depression and some anxiety disorders.
It can take a while for you to see improvements. Antidepressants take at least 2 weeks before they start to help. Your depression symptoms are likely to begin to improve after 4 to 6 weeks.
If you have severe depression, bipolar disorder or psychosis you may also be prescribed mood stabilisers or anti-psychotic drugs.
Best antidepressant for you
Deciding which antidepressant is best for you can be complex. Even if a treatment is proven to be effective, it may not be equally effective for every person.
To decide which antidepressant is best for you, your doctor might ask about your:
- medical history
- other medications.
If you’re female, they may ask if you’re pregnant or breastfeeding.
Your doctor might need to change your medication or dosage if it’s not working as well as expected. It can take time to find the antidepressant that works best for you.
Antidepressants side effects
Antidepressants won't change your personality or make you feel happy all the time. Possible side effects depend on the antidepressant medication. The likelihood of experiencing side effects also varies from person to person.
Common side effects of antidepressants include:
- nausea and weight gain
- headaches and dizziness
- anxiety and agitation
- sweating and dry mouth
- sexual difficulties – for example, difficulty becoming or staying aroused.
If you do experience side effects, tell your doctor – there are ways of reducing them. Some symptoms don’t last long and will go away by themselves.
Sometimes people with depression have suicidal thoughts. People are less likely to hurt themselves if the depression is treated effectively.
It can take more than two weeks for antidepressant medication to start to be effective. During this time you should be monitored closely by your doctor. The risk of suicidal behaviour may be slightly increased during this time, especially in young people.
Types of antidepressants
There’s a wide range of antidepressant medication available. We’ve listed the different types of antidepressants used in Australia.
Selective Serotonin Reuptake Inhibitors (SSRIs)
This class includes sertraline, citalopram, escitalopram, paroxetine, fluoxetine and fluvoxamine.
- the most commonly prescribed antidepressants in Australia
- often a doctor's first choice for most types of depression
- often used for obsessive compulsive disorder
- generally well tolerated by most people
- generally non-sedating.
Serotonin and Noradrenalin Reuptake Inhibitors (SNRIs)
This class includes venlafaxine, desvenlafaxine and duloxetine.
- have fewer side effects compared to SSRIs
- are often prescribed for severe depression
- are safer if a person overdoses.
Reversible Inhibitors of MonoAmine oxidase (RIMAs)
This class includes moclobemide.
- have fewer side effects
- are non-sedating
- may be less effective in treating more severe forms of depression than other antidepressants
- are helpful for people who are experiencing anxiety or sleeping difficulties.
TriCyclic Antidepressants (TCAs)
The class includes nortriptyline, clomipramine, dothiepin, imipramine and amitriptyline.
- effective, but have more harmful side effects than newer medications such as SSRIs
- more likely to cause low blood pressure
- often used for obsessive compulsive disorder.
Noradrenaline-Serotonin Specific Antidepressants (NaSSAs)
This class includes mirtazapine.
- relatively new antidepressants
- helpful when there are problems with anxiety or sleeping
- generally low in sexual side effects but may cause weight gain.
Noradrenalin Reuptake Inhibitors (NARIs)
This class includes reboxetine.
- designed to act selectively on one type of brain chemical – noradrenalin
- less likely to cause sleepiness or drowsiness than some other antidepressants
- more likely to cause difficulties with sleeping
After the initial doses, NARIs are more likely to cause:
- increased sweating
- sexual difficulties
- difficulty urinating
- increased heart rate.
Monoamine Oxidase Inhibitors (MAOIs)
This class includes tranylcypromine.
MAOIs are prescribed only under exceptional circumstances. They require a special diet and have adverse effects.
Agomelatine is an atypical antidepressant that stimulates melatonin receptors.
Common side effects include headaches and sleep disturbances.
In rare cases it can affect your liver and it’s not recommended for people who already have liver problems. Regular blood tests to monitor your liver function are usually recommended if you take agomelatine.
How long are antidepressants usually needed?
The length of time you need antidepressants depends on the severity of your condition and how you respond to treatment.
Some people only need to take antidepressants for 6 to 12 months. Others may need to take it for longer, just like someone with diabetes might use insulin or someone with asthma would use Ventolin.
Don’t stop taking your antidepressant medication suddenly. Stopping antidepressant medication should be:
- done gradually
- on a doctor's recommendation
- under supervision.
More information on medical treatments for anxiety and depression