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. We have added some references and sources of further information at the end of this leaflet.
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 types:
SSRIs (Selective Serotonin Reuptake Inhibitors)
SNRIs (Serotonin and Noradrenaline Reuptake Inhibitors)
NASSAs (Noradrenaline and Specific Serotoninergic Antidepressants)
MAOIs (Monoamine oxidase inhibitors)
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
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 ones?
Yes and no. The older tablets (Tricyclics) are just as effective as the newer ones (SSRIs) but, on the whole, the newer ones 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 the common antidepressants, their trade names in the UK, 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:
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 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.
The side-effects are very similar to SSRIs. They can make you feel drowsy, and cause weight gain, but they cause less sexual problems.
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.
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.
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 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.
flu like symptoms
vivid dreams or nightmares
sensations in the body that feel like electric shocks (see references)
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. You might like to read our leaflet about ‘Coming off antidepressants’.
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.
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 Health and Care Excellence (NICE) 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, people mature at different times. Young adults are more likely to commit suicide than older adults, so a young adult should be particularly closely monitored if they take an 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 you 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.
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 pharmacist.
How should antidepressants be taken?
Keep in touch with your doctor when you start treatment. They will monitor you for side-effects and how you feel. They may advise you to change the dose. It doesn’t help to increase the dose above the recommended levels. If you are being given the drug for anxiety, your doctor may suggest that you start on a very low dose for the first few weeks.
Try not to be put off if you get some side-effects. Many of them wear off in a week or so. 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.
How long will I have to take them for?
Antidepressants don’t necessarily treat the cause of the depression or take it away completely.
If you stop the medication before 6 to 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. Sometimes depressions get better by themselves. 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, keeping physically active, 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 helpful 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 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 Hypericum. This is made from a herb, St Johns Wort, and is available without prescription. Because it is a herbal treatment, it is less well researched and there may be variations in the preparations on sale. Another problem is that it can interfere with other medicines like ‘the pill’. 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 longer. 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 treatments?
Over a period of a year, many talking treatments are as effective as antidepressants. However, antidepressants may work faster (see references). Some studies suggest that it is best to combine antidepressants and psychotherapy. Unfortunately there can be a waiting list for talking treatments in some parts of the country.
Hypericum, or St John’s Wort, seems to be as effective as antidepressants in milder depression, although there is little evidence that it works in more severe depressions.
Physical activity 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:
Medication Trade name Group
Amitriptyline Tryptizol Tricyclic
Clomipramine Anafranil Tricyclic
Citalopram Cipramil SSRI
Dosulepin Prothiaden Tricyclic
Doxepin Sinequan Tricyclic
Duloxetine Cymbalta, Yentreve SNRI
Fluoxetine Prozac SSRI
Imipramine Tofranil Tricyclic
Lofepramine Gamanil Tricyclic
Mirtazapine Zispin NaSSA
Moclobemide Manerix MAOI
Nortriptyline Allegron Tricyclic
Paroxetine Seroxat SSRI
Phenelzine Nardil MAOI
Reboxetine Edronax SNRI
Sertraline Lustral SSRI
Tranylcypromine Parnate MAOI
Trazodone Molipaxin Tricyclic-related
Venlafaxine Efexor SNRI
SSRI = Selective Serotonin Reuptake Inhibitor
SNRI = Serotonin and Noradrenaline Reuptake Inhibitor
MAOI = Monoamine oxidase inhibitor
NaSSA=Noradrenergic and Specific Serotonergic Antidepressant