Aims of the leaflet

This leaflet is for anyone who wants to know more about antidepressants. It
discusses how they work, why they are prescribed, their effects and side-effects,
and alternative treatments. If your questions are not answered in this leaflet, there
are some references and sources of further information at the end of this leaflet.
Where there are areas of disagreement, we have given references to other
publications which will allow you to look into these issues for yourself. These include
the effectiveness of antidepressants, problems when you stop taking them, and
how they compare with other treatments. At the time of writing, these references
were available free and in full on the Internet.

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 almost
thirty different kinds of antidepressants available today and there are four main
 Tricyclics
 MAOIs (Monoamine oxidase inhibitors)
 SSRIs (Selective Serotonin Reuptake Inhibitors)
 SNRIs (Serotonin and Noradrenaline Reuptake Inhibitors)
 NASSAs (Noradrenaline and Specific Serotoninergic Antidepressants)

How do they work?

We don't know for certain, but we think that antidepressants work by increasing the
activity of certain chemicals work in our brains called neurotransmitters. They pass
signals from one brain cell to another. The chemicals most involved in depression
are thought to be Serotonin and Noradrenaline.

What are antidepressants used for?

Moderate to severe depressive illness (Not mild depression).
Severe anxiety and panic attacks
Obsessive compulsive disorders
Chronic pain
Eating disorders
Post-traumatic stress disorder.

If you are not clear about why an antidepressant has been suggested for you, ask
your doctor.

Antidepressants: The Royal College of Psychiatrists

Page 1

How well do they work?

After 3 months of treatment, the proportions of people with depression who will be
much improved are:

50% and 65% if given an antidepressant
compared with
25 - 30% if given an inactive "dummy" pill, or placebo

It may seem surprising that people given placebo tablets improve, but this happens
with all tablets that affect how we feel - the effect is similar with painkillers.
Antidepressants are helpful but, like many other medicines, some of the benefit is
due to the placebo effect.

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 so dangerous if someone
takes an overdose.

What kind of antidepressant have I been recommended?

At the end of the leaflet you can find a list of antidepressants, their trade names,
and their type.

Do antidepressants have side-effects?

Yes - your doctor will be able to advise you here. You should always remind him or
her of any medical conditions you have or have had in the past. Listed below are
the side effects you might experience with the different types of antidepressant:
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. Tricyclic antidepressants are dangerous in
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 - there is even more information about these
on the leaflets that come with the medication. However, most people get a small
number of mild side-effects (if any). The side-effects usually wear off over a couple
Antidepressants: The Royal College of Psychiatrists

Page 2

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 will pass once the depression starts to lift.
The side-effects are very similar to the SSRIs, although Venlafaxine should not be
used if you have a serious heart problem. It can also increase blood pressure, so
this may need to be monitored.
This type of antidepressant is rarely prescribed these days. MAOIs can give you a
dangerously high blood pressure if you eat foods containing a substance called
Tyramine. If you agree to take an MAOI antidepressant your doctor will give you a
list of foods to avoid.
The side-effects are very similar to SSRIs. It can make you feel drowsy, encourages
weight gain, but it causes less sexual problems.

What about driving or operating machinery?

Some antidepressants make you sleepy and slow down your reactions - the older
ones are more likely to do this. Some can be taken if you are driving. Remember,
depression itself will interfere with your concentration and make it more likely that
you will have an accident. If in doubt, check with your doctor.

Are antidepressants addictive?

Antidepressant drugs don't cause the addictions that you get with tranquillisers,
alcohol or nicotine, in the sense that:

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, up to a third of people who stop SSRIs and SNRIs have withdrawal
symptoms which can last between 2 weeks and 2 months.
These include:
 stomach upsets
 flue like symptoms
 anxiety
 dizziness
 vivid dreams or nightmares
 sensations in the body that feel like electric shocks (see references)

Antidepressants: The Royal College of Psychiatrists

Page 3

In most people these withdrawal effects are mild, but for a small number of people
they can be quite severe. They seem to be most likely to happen with Paroxetine
(Seroxat) and Venlafaxine (Efexor). It is generally best to taper off the dose of an
antidepressant rather than stop it suddenly.
Some people have reported that, after taking an SSRI for several months, they
have had difficulty managing once the drug has been stopped and so feel they are
addicted to it. Most doctors would say that it is more likely that the original
condition has returned.
The Committee of Safety of Medicines in the UK reviewed the evidence in 2004 and
concluded 'There is no clear evidence that the SSRIs and related antidepressants
have a significant dependence liability or show development of a dependence
syndrome according to internationally accepted criteria.'

SSRI antidepressants, suicidal feelings and young people

There is some evidence of increased suicidal thoughts (although not actual suicidal
acts) and other side-effects in young people taking antidepressants. So, SSRI
antidepressants are not licensed for use in people under 18. However, the National
Institute for Clinical excellence has stated that Fluoxetine, an SSRI antidepressant,
can be used in the under-18s.
There is no clear evidence of an increased risk of self-harm and suicidal thoughts in
adults of 18 years or over. But, individuals mature at different rates. Young adults
are more likely to commit suicide than older adults, so a young adult should be
particularly closely monitored if he or she takes an SSRI antidepressant.

What about pregnancy?

It is always best to take as little medication as possible while you are pregnant.
However, if you are one of those people who may need medication to stay well, it's
best to discuss the benefits and risks with your doctor. There are a number of
issues to consider. For example, you will need to think about:
 how ill you have been in the past
 the effect that being ill could have on your and your baby
 up-to-date information about the safety of antidepressants in pregnancy
 other treatments you could try such as Cognitive Behavioural Therapy.
For further information, see our leaflet on Mental health in pregnancy on

What about breastfeeding?

Many women do breastfeed while on antidepressants but, again, it's worth
discussing it with your doctor. As well as the issues listed above, you will need to
think about:
 the advantages of breastfeeding
 how much antidepressant enters your milk
 the risk of getting unwell again if you want to switch to a different medication
after you've had your baby
 whether your baby is premature or has any health problems.
Antidepressants: The Royal College of Psychiatrists

Page 4

What about the baby?

A baby will get only a small amount of antidepressant from mother's milk. Babies
older than a few weeks have very effective kidneys and livers. They are able to
break down and get rid of medicines just as adults do, so the risk to the baby is
very small.
Some antidepressants, like imipramine, nortriptyline and sertraline only get into the
breast milk in very small amounts – it is worth talking this over with your doctor or

How should antidepressants be taken?

Keep in touch with your doctor in the first few weeks. With some of the older
Tricyclic drugs it's best to start on a lower dose and work upwards over the
next couple of weeks. If you don't go back to the doctor and have the dose
increased, you could end up taking too little. You usually don't have to do
this with the SSRI tablets. The dose you start with is usually the dose you
carry on with. It doesn’t help to increase the dose above the recommended

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. If you feel worse
it is important to tell your doctor so that he can decide if the medicines are
right for you. Your doctor will also want to know if you get increased feelings
of restlessness or agitation.

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 driving - or with anything you need to
concentrate on.

Keep them out of the reach of children.

Tempted to take an overdose? Tell your doctor as soon as possible and give
your tablets to someone else to keep for you.

Tell your doctor about any major changes in how you feel when the dose of
antidepressant is changed.

Antidepressants: The Royal College of Psychiatrists

Page 5

How long will I have to take them for?

Antidepressants don't necessarily treat the cause of the depression or take it away
completely. Without any treatment, most depressions will get better after about 8
If you stop the medication before 8 or 9 months is up, the symptoms of depression
are more likely to come back. The current recommendation is that it is best to take
antidepressants for at least six months after you start to feel better. It is
worthwhile thinking about what might have made you vulnerable, or might have
helped to trigger off your depression. There may be ways of making this less likely
to happen again.
If you have had two or more attacks of depression then treatment should be
continued for at least two years.

What if the depression comes back?

Some people have severe depressions over and over again. Even when they have
got better, they may need to take antidepressants for several years to stop their
depression coming back. This is particularly important in older people, who are
more likely to have several periods of depression. For some people, other drugs
such as Lithium may be recommended. Psychotherapy may be helpful in addition to
the tablets.

What will happen if I don't take them?

It's difficult to say - so much depends on why they have been prescribed, on how
bad your depression is and how long you've had it for. It's generally accepted that
most depressions resolve themselves naturally within about 8 months. If your
depression is mild it is best to try some of the other treatments mentioned later in
this leaflet. If you can’t decide, talk it over with your doctor.

What other treatments of depression are available?

It is not enough just to take the pills. It is important to find ways of making
yourself feel better, so you are less likely to become depressed again. These can
include finding someone you can talk to, taking regular exercise, drinking less
alcohol, eating well, using self-help techniques to help you relax and finding ways
to solve the problems that have brought the depression on. For some tips on selfhelp, see our leaflet on depression.

Talking treatments

There are a number of effective talking treatments for depression. Counselling is
useful in mild depression. Problem solving techniques can help where the
depression has been caused by difficulties in life. Cognitive Behavioural Therapy
was developed to treat depression and helps you to look at the way you think about
yourself, the world and other people. For information about these and other forms
of psychotherapy, see our leaflets on Psychotherapy and Cognitive Behavioural

Antidepressants: The Royal College of Psychiatrists

Page 6

Herbal remedies

There is also a herbal remedy for depression called Hypericum. This is made from a
herb, St John’s Wort, and is available without prescription. It seems to work in
much the same way as some antidepressants, but some people find that it has
fewer side-effects. One problem is that it can interfere with the way other
medications work. If you are taking other medication, you should discuss it with
your doctor.


You may find that you get depressed every winter but cheer up when the days
become sunnier. This is called seasonal affective disorder (SAD). If so, you may
find a light box helpful - this is a source of bright light which you have on for a
certain time each day and which can make up for the lack of light in the winter. For
further information, see our leaflet on SAD at

How do antidepressants compare with these other treatments?

Recent studies have suggested that over a period of a year, many of these
psychotherapies are as effective as antidepressants. It is generally accepted that
antidepressants work faster (see references). Some studies suggest that it is best
to combine antidepressants and psychotherapy. Unfortunately some of these
therapies are not readily available within the NHS in some parts of the country.
Hypericum, or St John's Wort, is widely used as an antidepressant in Germany. It
seems to be as effective as antidepressants in milder depression, although there is
little published evidence for its effectiveness in moderate to severe depressions.
Exercise and self-help books based on Cognitive Behavioural Therapy can be
effective treatments for depression. If you have any further questions about
antidepressants which haven't been covered in this leaflet, take a look at the
further reading section and have a word with your doctor or psychiatrist. It's also
good to talk things over with your family or friends.
Antidepressants in common use:
























Antidepressants: The Royal College of Psychiatrists

Page 7




























Tranylcypromine Parnate








SSRI = Selective Serotonin Reuptake
SNRI = Serotonin and Noradrenaline
Reuptake Inhibitor
MAOI = Monoamine oxidase inhibitor
NaSSA=Noradrenergic and Specific
Serotonergic Antidepressant

Further help:

You can get further information on antidepressants from the Choice and Medication
website: This offers information about
medications used in the mental health to help people make informed decisions.
For a full list of side-effects please visit and type in the
name of the medicine in the 'Search for:' section at the top of the page.


At the time of writing, these are available in full on the Internet.
Antidepressant drugs and generic counselling for treatment of major depression in
primary care: randomised trial with patient preference. British Medical Journal
(2001) 322: 772 (31 March). Compares antidepressants and counselling.
Antidepressant discontinuation reactions. British Medical Journal (1998) 316: 11051106 (11 April).
Antidepressants: The Royal College of Psychiatrists

Page 8

Depression in primary care, Vol 2. Treatment of major depression by M.D
Rockville, US Department of Health and Human Services. (1993) Clinical practice
guidelines No. 5. A review of the effectiveness of antidepressants and other
treatments of depression.
NICE guidelines on antenatal and postnatal mental health published 2007
Information on antidepressant safety from the MHRA. Selective serotonin re-uptake
Paroxetine safety in pregnancy- Questions and Answers:

For further information contact:
Association for Postnatal Depression: Helpline: 020 7386 0868 (10am- 2pm
Mon, Weds and Fri and 10am- 5pm, Tues and Thurs).
Provides support to mothers suffering from post-natal illness. It exists to increase
public awareness of the illness and to encourage research into its cause and nature.
Aware : Helpline: 00 353 1 90 303 302; Tel: 00 353 1 661 7211. Provides
information and support to people affected by depression in Ireland and Northern
Depression Alliance: Tel: 0845 123 23 20; [email protected]
Information, support and understanding for people who suffer with depression, and
for relatives who want to help. Self-help groups, information, and raising awareness
for depression.
NHS Direct A 24-hour nurse-led helpline providing confidential healthcare advice
and information. Tel: 0845 46 47
The electronic Medicines Compendium (eMC): summaries of Drugs and
Patient Information Leaflets (PILs). Information on thousands of licensed medicines
available in the UK. Continuously updated.
This leaflet was produced by the Royal College of Psychiatrists' Public Education
Editorial Board.
Series Editor: Dr Philip Timms
Expert Review: Public Education Editorial Board and Dr Lucinda Green (section on
Updated: September 2010
Review date: September 2012
With grateful thanks to Karen O’Rourke from Northumberland, Tyne and Wear NHS
Foundation Trust

Antidepressants: The Royal College of Psychiatrists

Page 9

© Royal College of Psychiatrists. This leaflet may be downloaded, printed out,
photocopied and distributed free of charge as long as the Royal College of
Psychiatrists is properly credited and no profit is gained from its use. Permission to
reproduce it in any other way must be obtained from the Head of Publications. The
College does not allow reposting of its leaflets on other sites, but allows them to be
linked to directly.
Charity registration number (England and Wales) 228636 and in Scotland
For further information on mental health problems and their treatment, visit

Antidepressants: The Royal College of Psychiatrists

Page 10

Antidepressants 9.4 of 10 on the basis of 1928 Review.