Antidepressants are used to treat depression. Depression is a mental health condition which is characterised by a long-term lack of energy, ambition and concentration, coupled with low self-esteem, low mood and low self-worth. There are two main types of antidepressant medication; these are known as tricyclics and SSRIs (selective serotonin re-uptake inhibitors).

How do antidepressants work?

Scientists do not really understand why the chemical balance in the brain changes when a person develops depression; consequently, they also don’t really understand how antidepressants work. However, research has suggested that depression is caused by a decrease in the levels of noradrenaline and serotonin, which are thought to cause low mood. Tricylics increase the levels of noradrenaline and serotonin and SSRIs increase the levels of serotonin.

Are there any side-effects of antidepressants?

Some people experience side-effects when taking antibiotics; common side-effects include:

  • Tiredness
  • Drowsiness
  • Constipation
  • Blurred vision
  • A dry mouth
  • Changes in body temperature and sweating
  • Trouble urinating

Usually, side-effects are more common with tricyclics than SSRIs.

Are antidepressants safe for everyone?

Some people may not be given antidepressants because they may interfere with other types of medication and may make existing conditions worse; examples of these people include people with heart, liver or kidney problems, pregnant women and children under the age of 18. Prolonged use of antidepressants is usually not recommended as people can get mildly addicted to them; the tablets themselves are not addictive but they can cause withdrawal symptoms which can be particularly nasty. Many doctors will prescribe antibiotics alongside courses of counselling and therapy; this is often much more effective than medication alone.

Guide to Medication






Contraceptive medication

Beta blockers