Antidepressants are medicines that treat the symptoms of depression. There are almost 30 different kinds available.
Most people with moderate or severe depression benefit from antidepressants, but not everybody does. You may respond to one antidepressant but not to another, and you may need to try two or more treatments before you find one that works for you.
The different types of antidepressant work about as well as each other. However, side effects vary between different treatments and people.
When you start taking antidepressants, you should see your GP or specialist nurse every week or two for at least four weeks to see how well they are working. If they are working, you'll need to continue taking them at the same dose for at least four to six months after your symptoms have eased.
If you've had bouts of depression in the past, you may need to continue to take antidepressants for up to five years or longer.
Antidepressants aren't addictive, but you may get some withdrawal symptoms if you stop taking them suddenly or you miss a dose (see below).
Selective serotonin reuptake inhibitors (SSRIs)
If your GP thinks you would benefit from taking an antidepressant, you'll usually be prescribed a modern type called a selective serotonin reuptake inhibitor (SSRI). Examples of commonly used SSRI antidepressants are Seroxat (paroxetine), Prozac (fluoxetine) and Cipramil (citalopram).
They help increase the level of a natural chemical in your brain called serotonin, which is thought to be a "good mood" chemical.
SSRIs work just as well as older antidepressants and have fewer side effects.
They can, however, cause nausea and headaches, as well as a dry mouth and problems having sex. However, all these negative effects usually improve over time.
Some SSRIs aren't suitable for children under the age of 18. Research shows that the risk of self-harm and suicidal behaviour may increase if they're taken by under-18s. Fluoxetine is the only SSRI that can be prescribed for under-18s, and even then only when a specialist has given the go-ahead.
Tricyclic antidepressants (TCAs)
This group of antidepressants is used to treat moderate to severe depression.
TCAs, which includes Imipramil (imipramine) and amitriptyline, have been around for longer than SSRIs.
They work by raising the levels of the chemicals serotonin and noradrenaline in your brain. These both help lift your mood.
They're generally quite safe, but it's a bad idea to smoke cannabis if you are taking TCAs because it can cause your heart to beat rapidly.
Side effects of TCAs may include a dry mouth, blurred vision, constipation, problems passing urine, sweating, light-headedness and excessive drowsiness, but vary from person to person.
The side effects usually ease after seven to 10 days, as your body gets used to the medication.
New antidepressants, such as Efexor (venlafaxine), Cymbalta or Yentreve (duloxetine) and Zispin Soltab (mirtazapine), work in a slightly different way from SSRIs and TCAs.
Venlafaxine and duloxetine are known as SNRIs (serotonin-noradrenaline reuptake inhibitors). Like TCAs, they change the levels of serotonin and noradrenaline in your brain.
Studies have shown that an SNRI can be more effective than an SSRI, though they're not routinely prescribed as they can lead to a rise in blood pressure.
Antidepressants are not addictive in the same way that illegal drugs and cigarettes are, but when you stop taking them you may have some withdrawal symptoms, including:
- upset stomach
- flu-like symptoms
- vivid dreams at night
- sensations in the body that feel like electric shocks
In most cases these are quite mild and last no longer than a week or two, but occasionally they can be quite severe. They seem to be most likely to occur with paroxetine (Seroxat) and venlafaxine (Efexor).
Withdrawal symptoms occur very soon after stopping the tablets, so can easily be told apart from symptoms of depression relapse, which tend to occur after a few weeks.
Common questions about antidepressants answered:
How long does it take for antidepressants to work?
Can I drink alcohol if I'm taking antidepressants?
How should antidepressants be stopped?