This information may be helpful if you have been prescribed or are using benzodiazepines or know someone who is, or are worried about addiction and withdrawal effects.


This webpage provides information, not advice. You should read our full disclaimer before reading further.

This information reflects the best available evidence at the time of writing. We aim to review our mental health information every three years, and update critical changes more regularly.

©  March 2015 Royal College of Psychiatrists 

A group of medications which have been used since the 1960s to treat:

  • anxiety
  • agitation and restlessness, particularly for people in hospital
  • epileptic seizures/fits
  • mania
  • alcohol withdrawal
  • sleeping problems

They replaced the barbiturates which had been commonly prescribed for 50 years up to the 1950s, but which were addictive and very dangerous in overdose.

Benzodiazepines all work in a similar way (see below). The shorter-acting ones have been marketed as sleeping tablets – the idea being that you don't get a muzzy head the next day.  The longer-acting ones have been marketed for their use in controlling anxiety.

They boost the effect of a substance in the brain – called GABA (Gabba Amino Butyric Acid).

This is a neurotransmitter – a chemical which is used in the brain to control the passage of messages from one cell to another. GABA has a generally calming effect in the human brain.

  • Sleepiness
  • Unsteadiness
  • Problems with memory and concentration.

These side-effects affect older people much more.

Benzodiazepines should generally not be prescribed to people over the age of 60.

Occasionally benzodiazepines can make a person feel more agitated or even aggressive.

Yes. Around 4 in every 10 people who take them every day for more than 6 weeks will become addicted. The signs are that you:

  • feel bad if you don't take them
  • find you have to take more and more to get the same effect
  • crave them
  • get withdrawal symptoms if you try to stop. You:
  • can't sleep
  • feel tense and agitated
  • feel dizzy
  • can get odd metallic tastes in your mouth, odd feelings like electric shocks in your arms and legs
  • have blurred vision, sensitivity to light.

These usually start within 48 hours of stopping or reducing the dose of benzodiazepine. You may find them mild and that they pass off within a few days.

However, some people have severe symptoms. You may

  • become confused
  • have hallucinations (hearing and seeing things that aren't there)
  • have epileptic fits.

This is similar to alcohol withdrawal. You are more likely to have such symptoms if you have been taking higher doses of a benzodiazepine.

These symptoms will usually last for days or weeks, depending on whether you have been taking a long- or short-acting benzodiazepine.

Some people go on to have unpleasant symptoms for many months or even years.

If you have taken a benzodiazepine every day for more than 3 weeks or so, you should not stop them suddenly.

It's safest to stop them gradually, by reducing the daily dose every 2 - 4 weeks, by 1/8 or a 1/4. of the original dose - although some people find they need to do it in smaller steps.

It is better to reduce too slowly rather than too quickly, even if this takes months or years.

Some benzodiazepines are harder to come off than others - such as the shorter-acting ones like Lorazepam.

If you are finding it hard to stop one of these, your doctor can change it to Diazepam which can be easier to withdraw from.

Apart from the real problems with addiction and withdrawal, benzodiazepines are otherwise safe for adults of working age and no routine tests are needed before taking them.

They can be helpful in the short-term treatment of both anxiety and sleep problems.

They can also be used for the short-term treatment of generalised anxiety and social anxiety. They have been used in panic and obsessive compulsive disorders, but antidepressants - especially the SSRIs - are more effective.

In all the conditions in which they are used, benzodiazepines tend to produce dependence and withdrawal reactions. 

So - benzodiazepines should only be used for periods of up to 4 weeks.

The main treatments for anxiety and sleep problems are now psychological (see our leaflets on  Cognitive Behavioural Therapy and  Sleep Problems). For more severe anxiety, SSRI antidepressants can be used.

For the short-term relief of disturbed sleep, a new class of sedative drugs was introduced some years ago - the "Z" drugs - zaleplon, zolpidem and zopiclone.

These were marketed as being less addictive than benzodiazepines but work in a similar way, through the GABA system. There is not enough evidence to show that they are less likely to cause dependence than benzodiazepines.

The advice for their use is, therefore, much the same as for benzodiazepines - only when psychological methods have failed, at the lowest dose possible, and for short periods of time.

Up to 4 weeks - no longer. This should really be just to give other (often psychological) treatments a chance to work.

A few people may benefit from taking benzodiazepines long-term, or from time-to-time. This should only be carried out by a specialist unit after other treatments have been tried and have failed.

The main differences are:

  • how quickly they start to act
  • how long they stay in the body.

A short-acting drug is better to help sleep, so that you don't get a 'hangover' effect the next day - this can make it dangerous to drive, or use machinery. 

For anxiety that is there all the time, a longer-acting benzodiazepine such as diazepam could be more helpful.

If you are both anxious and sleeping badly, the longer-acting benzodiazepines can be taken at night - they will improve sleep, but will still be working the next day to help with the anxiety.

Whether long or short acting, all benzodiazepines can be addictive (see above).

You can find how to help yourself with anxiety and insomnia from books or through the internet.

See the reading materials section at the end of this leaflet and at the end of our other leaflets such as:

Anxiety and insomnia can be short-lived, especially when they come after a stressful event, such as a bereavement or losing a job.

However, these problems can be due to depression, chronic stress, or relationship problems.

Benzodiazepines do not help with these issues - see our leaflets on  Anxiety and  Sleep Problems


We know that the benzodiazepines and z-drugs can help in anxiety and insomnia. But we also know that they are addictive.

These medications were greatly overused in the 1960s and 1970s which is why so many people are still dependent on them today.

It does seem safe to use them, with caution, in the short-term (less than 4 weeks). But they are best avoided if you have a history of dependence on other substances.

For anything more than a few weeks, psychological therapies and/or antidepressants are the best treatments for most people.

  • Nutt, DJ & Ballenger, JC. (2003) Anxiety disorders. Blackwell Science Limited, Oxford. I-xii, 1-542. ISBN 0-632-05938-9.
  • Doble A, Martin IL, Nutt DJ. (2004) Calming the brain: benzodiazepines and related drugs from laboratory to clinic. Martin Dunitz Limited, London. i-vi, 1-185. ISBN 1-84184-05201.
  • Wilson SJ and Nutt DJ (2008) Sleep Disorders; Oxford Psychiatry Library.
  • British National Formulary: information on hypnotics and anxiolytics 



This information was produced by the Royal College of Psychiatrists Public Education Editorial Board.
Series Editor: Dr Philip Timms.