Depression and low mood (BSL version)

In this video, an expert describes the various levels of depression, the early warning signs and the treatments available.

Media last reviewed: 30/09/2013

Next review due: 30/09/2015

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine that you are taking. It is run by a medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA). See the Yellow Card Scheme website for more information.

Antidepressants are a type of medication used to treat depression or prevent it recurring.

They can also be used to treat a number of other conditions, including:

Antidepressants are also sometimes used to treat people with long-term (chronic) pain.

Read more about when antidepressants are used.

How antidepressants work

It is thought antidepressants work by increasing levels of a group of chemicals in the brain called neurotransmitters. Certain neurotransmitters, such as serotonin and noradrenaline, can improve mood and emotion, although this process is not fully understood.

Increasing levels of neurotransmitters can also disrupt pain signals sent by nerves, which may explain why some antidepressants can help relieve long-term pain.

While antidepressants can help treat the symptoms of depression, they do not always address its causes. This is why they are usually used in combination with therapy to treat more severe depression or other mental health conditions caused by emotional distress.

How effective are antidepressants?

Most people benefit from taking antidepressants to some degree, but research suggests that antidepressants may not be as effective as previously thought in cases of mild depression.

However, they are the most effective treatment in relieving symptoms quickly, particularly in cases of severe depression.

The Royal College of Psychiatrists estimates that 50-65% of people treated with an antidepressant for depression will see an improvement, compared to 25-30% of those taking inactive “dummy” pills (placebo). This means that most people do benefit from antidepressants, even if it is sometimes a result of the placebo effect.

Doses and duration of treatment

Antidepressants are usually taken in tablet form. When they are prescribed, you will start on the lowest possible dose thought necessary to improve your symptoms.

Antidepressants usually need to be taken for 2-4 weeks (without missing a dose) before the benefit is felt. It's important not to stop taking them because you get some mild side effects early on, as these effects will usually wear off quickly.

If you take an antidepressant for 4-6 weeks without feeling any benefit, speak to your GP or mental health specialist. They may recommend increasing your dose or trying an alternative medication.

A course of treatment usually lasts for six months, although a two-year course may be recommended for people with a previous history of depression and some people with recurrent depression may be advised to take them indefinitely.

Read more about antidepressant doses.

Side effects

Different antidepressants can have a range of different side effects. Always check the information leaflet that comes with your medication to see what the possible side effects are. Common side effects of antidepressants in general are usually mild and can include:

Side effects should improve within a few days or weeks of treatment as the body gets used to the medication.

Read more about the side effects of antidepressants and cautions and interactions of antidepressants.

Different types of antidepressants

There are a number of different types of antidepressants. Some of the most widely used types are discussed below.

Selective serotonin reuptake inhibitors (SSRIs)

SSRIs are the most widely prescribed type of antidepressants. They are usually preferred over other antidepressants as they cause fewer side effects. An overdose is also less likely to be serious.

Fluoxetine is probably the best known SSRI (sold under the brand name Prozac). Other SSRIs include citalopram (Cipramil), paroxetine (Seroxat) and sertraline (Lustral).

Serotonin-noradrenaline reuptake inhibitors (SNRIs)

SNRIs are similar to SSRIs. They were designed to be a more effective antidepressant than SSRIs. However, the evidence that SNRIs are more effective in treating depression is uncertain. It seems some people respond better to SSRIs while others respond better to SNRIs.

Examples of SNRIs include duloxetine (Cymbalta and Yentreve) and venlafaxine (Efexor).

Tricyclic antidepressants (TCAs)

Tricyclic antidepressants (TCAs) are an older type of antidepressant. They are no longer usually recommended as a first-line treatment for depression because they can be more dangerous if an overdose is taken. They also cause more unpleasant side effects than SSRIs and SNRIs.

Exceptions are sometimes made in people with severe depression that fails to respond to other treatments. TCAs may also be recommended for other mental health conditions such as obsessive compulsive disorder and bipolar disorder.

Examples of TCAs include amitriptyline (Tryptizol), clomipramine (Anafranil), imipramine (Tofranil), lofepramine (Gamanil) and nortriptyline (Allegron).

Some types of TCAs, such as amitriptyline, can also be used to treat chronic nerve pain.

Monoamine oxidase inhibitors (MAOIs)

Monoamine oxidase inhibitors (MAOIs) are another older type of antidepressant with a wide range of side effects that are rarely used nowadays. They tend only to be used if other types of antidepressants are not effective and should only be taken under the supervision of a psychiatrist.

A significant drawback of MAOIs is the need to avoid certain foods and drinks, such as cheese and pickled fish, which contain a protein called tyramine. This is because consuming tyramine while taking MAOIs can cause a dangerous rise in blood pressure.

Examples of MAOIs include moclobemide (Manerix) and phenelzine (Nardil).

Alternatives to antidepressants

Alternative treatments for depression include talking therapies such as cognitive behavioural therapy (CBT).

Increasingly, people with moderate to severe depression are treated using a combination of antidepressants and CBT. Antidepressants work quickly in reducing symptoms, whereas CBT takes time to deal with causes of depression and ways of overcoming it.

Regular exercise has also been shown to be useful in those with mild depression.

Read more about alternatives to antidepressants.

Page last reviewed: 01/10/2013

Next review due: 01/10/2015


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The 10 comments posted are personal views. Any information they give has not been checked and may not be accurate.

Amelia7777 said on 14 June 2014

I am taking Prozac 20mg and have not noticed any difference. If I'm not getting any side effects does that also mean that it is having no effect (as in working)?

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F_Muir said on 23 February 2014

Hi. I live in Scotland and can't get antidepressants despite being a victim of bullying, and was wondering how others are having access to medicine. I don't get any medical help at all. This is breach of my basic human rights. I'm a British citizen, was born and raised here and yet tourists have more rights than I do.

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ComradeEliskaya said on 23 July 2013

Firstly, I fully understand that you can't just turn up and expect to be prescribed antidepressants and they don't magically solve your problems but this is simply a question.
I am 17 and want to know that if I went to my GP and they did prescribe me any sort of antidepressant medication, would they have to make my parents aware of this, or would I be able to decide whether or not they knew?

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Dee100 said on 10 June 2013

Have been suffering with dental pain last 7 weeks,been back to dentist numerous times & no problems found.Today I was seen by dental consultant & was told he 98% sure its nerve pain.He has prescribed Nortriptyline.Im bit apprehensive as have just googled name and it says they are antidepressants.Am very confused and worried about taking them.

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Bayleen said on 29 October 2012

I'm 16 and i went to see my GP almost 2 weeks ago and i told her that i might be suffering from depression.Probably bipolar (my mum had bipolar so i know a lot about it) I told her that when i feel depressed i become really crazy. I argue with everyone ,i cry all the time,i self harm,i break things etc. and sometimes i get really manic. i have so much energy that i just can't be still. Sometimes it's good because i have a lot of energy to do things but that 'good' turn into a 'bad'. I feel like i can do and achieve anything and i start doing many things at once but then i fail at them because i get really tired at the end of the week and the fact that i failed makes me sad and angry and it turns into depression's been like that since i was about 9. traumatic things happened to me when i was 9 and i couldn't talk about it to anybody until 3 weeks ago. Anyway! When i told her (my GP) all of this she didn't really react to it. I think she thinks that i'm lying.I know that usually people in my position don't try to help themselves because they don't want to admit that they have a problem but i DO want to help myself and i'm scared and sometimes i feel like i'm ok but once i become depressed again (which happens every month) i get so crazy and i don't like it. I'm scared and i want it to stop. I just want to be normal like others. i want my mood to be stable. I've tried counseling but it just doesn't help. my mum used to take medication and it made her feel better and she wasn't so depressed. Could a 16 year old like me get medication to make my moon more stable? What if my GP says that i'm ok? Know that i'm not ok and it's not because i'm a teenager with normal teen ups and lows...i'm really tired and i just want for everything to stop. i want and need help. I have an appointment this week because my GP gave me some sheet that i need to fill in. I need to write some sort of situation on top and then write what that situation makes me feel like, think of etc.

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RosieTalk said on 09 September 2011

Hi Kate,

Thank you for your contribution to NHS Choices.

You must speak to your GP about the problems you are facing, but there are also lots of other people you can talk to. They can advise on the next steps to take it, be it antidepressants or a counsellor. You can also visit Mind for advice on where to seek help. The Site has some very useful information for young people: You can visit for advice, email or call 08457 90 90 90.

You should also visit A&E if you are having suicidal thoughts. They will have a crisis team on hand to help you.

Rosie Cowling, NHS Choices UGC team

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katet97 said on 03 September 2011

hi im 14
and i just took the test above and it said i am possibly depressed and i was wondering how i could get anti depressants because ive been feeling like this for about 5 years now and ive harmed myself and attempted suicide about 6 times and i go to councilling at school but it doesnt help at all

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cherry little said on 25 February 2011

Thank you for that , Rosietalk.
Very useful.

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RosieTalk said on 25 February 2011

Hi cherry little,

there is some more information on antidepressants here:

and here:

There is general advice on depression on the Live Well pages:

Rosie, NHS Choices UGC team

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cherry little said on 24 February 2011

This is great as the overview, but I can't find out much about the particular antidepressants.
Could you give a link to site where this could be found?
Also I think it would be useful to link into a site where we can find out about the "change over " process between the different types...recently I saw a CMH doctor who recommemded I change my medication. Feeling unstable at the time and knowing I am prone to suicidal thoughts, I was scared about reducing medication, so I asked him what the cross over involved. He refused to tell me, saying my GP would deal with it.
But when I got to the GP, she didn't have a clue!
So I decided not to risk it.. If I could have found out more details myself, I could have informed the GP and maybe we could have worked something out.

Many thanks .

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