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 five main
- MAOIs (Monoamine oxidase inhibitors)
- SSRIs (Selective Serotonin Reuptake Inhibitors)
- SNRIs (Serotonin and Noradrenaline Reuptake Inhibitors)
- NASSAs (Noradrenaline and Specific Serotoninergic
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
- 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.
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
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
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
What kind of antidepressant have I been
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 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
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 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
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
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
The side-effects are very similar to SSRIs. It can make you
feel drowsy, encourages weight gain, but it causes less sexual
For a full list of side
effects please visit emc.medicines.org.uk and
type in the name of the medicine in the 'Search for:' section at
the top of the page.
What about driving or operating
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
- you won't find yourself craving them if you stop taking
However, up to a third of people who stop SSRIs and
SNRIs have withdrawal symptoms which can last between 2 weeks and 2
- stomach upsets
- flu like symptoms
- vivid dreams or nightmares
- sensations in the body that feel like electric shocks (see
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
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
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
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 you and your baby
- up-to-date information about the safety of
antidepressants in pregnancy
- other treatments you could try such as Cognitive Behavioural
For further information, see our leaflet on Mental health in
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.
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
- Tell your doctor about any major changes in how you feel when
the dose of antidepressant is changed.
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 months.
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
What other treatments of depression are
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 self-help, see our leaflet on depression.
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 Therapy
There is also a herbal remedy for depression called
This is made from a
herb, St Johns 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
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.
How do antidepressants compare with these other
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
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
Exercise and self-help books based on Cognitive Behavioural
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:
|SSRI = Selective Serotonin Reuptake Inhibitor
|SNRI = Serotonin and Noradrenaline Reuptake
|MAOI = Monoamine oxidase inhibitor
|NaSSA=Noradrenergic and Specific Serotonergic
At the time of writing, these are available in full on the
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: 1105-1106 (11 April).
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
guidelines on antenatal and postnatal mental health published
For further information contact:
Tel: 020 7386 0868. 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.
Helpline: 00 353
1890 303 302. Provides information and support to people affected
by depression in Ireland and Northern Ireland.
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.
: 111 from any landline or
mobile phone free of charge.Some areas of the country are
still covered by the 0845 4647 service. Click here
to find out if you live in an 0845 area.
This leaflet was
produced by the Royal College of Psychiatrists' Public Education
Series Editor: Dr Philip Timms
Expert Review: Public Education Editorial Board
and Dr Lucinda Green (section on pregnancy)
Updated: June 2012 Review date: June
With grateful thanks to Karen O’Rourke from
Northumberland, Tyne and Wear NHS Foundation Trust
This leaflet reflects the best available evidence at the time of
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