We are working with Barnet, Enfield and Haringey Mental Health NHS Trust as the North London Mental Health Partnership.

Depression medication

What are antidepressants?

Antidepressants are drugs that relieve the symptoms of depression. They were first developed in the 1950s and have been used regularly since then. There are several different types, but here we will concentrate on the older "tricyclic" antidepressants and the newer "SSRIs" (Selective Serotonin Reuptake Inhibitors) since these two types account for 95% of antidepressants prescribed. There is a newer group called "SNRIs" (Serotonin and Noradrenaline Reuptake Inhibitors).

How do they work?

There are almost thirty different kinds of antidepressants available today. They all work by altering the way in which certain chemicals work in our brains. These chemicals are made by our body and are called neuro-transmitters.

Neuro-transmitters are the chemicals which transmit signals between the cells in our brains. In depression, some of the neurotransmitter systems, particularly those of Serotonin and Noradrenaline, don't seem to be working properly. We think that antidepressants work by increasing the activity of these chemicals in our brains.

What are antidepressants used for?

They are used to treat moderate to severe depression or to help the symptoms of severe anxiety, panic attacks and obsessional problems. They may also be used to help people with chronic pain, eating disorders and post-traumatic stress disorder. 

Don't assume that because you have been prescribed an antidepressant that this means you are suffering from depression. If you are not clear about why you have been given them, ask your doctor.

Are the newer ones better than the older ones?

Yes and no. The older tablets (Tricyclics) are just as effective as the newer ones (SSRIs) but, on the whole, the newer ones seem to have fewer side effects. A major advantage for the newer tablets is that they are not dangerous if someone takes an overdose of them.

Do antidepressants have side effects?

People experience different side effects. It is important to be aware of any you experience and helpful to keep a record of them yourself. To do this you may find it helpful to use the personal medication log.

Here is some information about the more common side effects


These commonly cause a dry mouth, a slight tremor, fast heartbeat, constipation, sleepiness, and weight gain. Particularly in older people, they may cause confusion, slowness in starting and stopping when passing water, faintness through low blood pressure, and falls. If you have heart trouble, it may be best not to take one of this group of antidepressants. Men may experience difficulty in getting or keeping an erection, or delayed ejaculation. Tricyclics are dangerous in overdose.


During the first couple of weeks of taking them, you may feel sick and more anxious. Some of these tablets can produce nasty indigestion, but you can usually stop this by taking them with food. More seriously, they may interfere with your sexual function. There have been reports of episodes of aggression, although these are rare.

The list of side effects looks worrying however, most people get a small number of mild side effects (if any). The side effects usually wear off over a couple of weeks as your body gets used to the medication. It is important to have this whole list, though, so you can recognise side effects if they happen. You can then talk them over with your doctor. The more serious ones - problems with urinating, difficulty in remembering, falls, confusion - are uncommon in healthy, younger or middle-aged people.

It is common, if you are depressed, to think of harming or killing yourself tell your doctor. Suicidal thoughts should pass once the depression starts to lift.

What about driving or operating machinery?

Some antidepressants make you sleepy and slow down your reactions while others are fine to take when driving. Please check the leaflets enclosed with the medication to ensue you are aware of the possible side-effects. Remember, depression itself will interfere with your concentration and make it more likely that you will have an accident.

Are antidepressants addictive?

Antidepressant drugs don't cause the addictions that you get with tranquillisers, alcohol or nicotine. You don't need to keep increasing the dose to get the same effect. You won't find yourself craving them if you stop taking them.

However, studies have shown that up to a third of people have withdrawal symptoms for a short time when they stop antidepressants. These include stomach upsets, flu like symptoms, anxiety, dizziness, vivid dreams at night or sensations in the body that feel like electric shocks.

They seem to be most likely to happen with an SSRI antidepressant called Paroxetine (Seroxat), but can be prevented by slowly reducing the dose of antidepressant rather than stopping it suddenly.

What about pregnancy?

It is always best to take as little medication as possible during pregnancy, especially during the first 3 months. However, some mothers-to-be do take antidepressants and evidence shows this babies don't have any harmful effects from this.

How should antidepressants be taken?

  • Try not to be put off if you get some side effects, many of them wear off in a few days. Don't stop the tablets unless the side effects really are unpleasant. If they are, get an urgent appointment to see your doctor.
  • Take them every day, if you don't, they won't work.
  • Wait for them to work. They don't work straight away. Most people find that they take 1-2 weeks to start working and maybe up to 6 weeks to give their full effect.
  •  Persevere. Stopping too early is the commonest reason for people not getting better and for the depression to return.
  • Try not to drink alcohol. Alcohol on its own can make your depression worse, but it can also make you slow and drowsy if you are taking antidepressants. This can lead to problems with concentration.
  • Keep them out of the reach of children.
  • If you are tempted to take an overdose please tell your doctor as soon as possible and give your tablets to someone else to keep for you.

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