Young people under the age of 18 should not be prescribed the controversial drug Seroxat, government advisors have ruled.
Seroxat is used in the treatment of depression and anxiety disorders
It follows a review which found children taking the anti-depressant may be more likely to self-harm or partake in suicidal behaviour.
The Medicines and Healthcare products Regulatory Agency (MHRA) has also warned that adults who are on the drug should not suddenly stop taking it.
Authorities in Europe and the United States are expected to review their advice on Seroxat in light of the agency's findings.
The Department of Health launched the review of Seroxat and similar drugs, known as SSRIs (Selective Serotonin Re-uptake Inhibitors) in January.
It followed claims from patient groups that the drug has serious side-effects and is addictive.
A recent investigation by the BBC's Panorama programme also raised concerns about the drug.
Young people under 18 years currently taking Seroxat for depression should consult their doctor
Seroxat has been available in the UK for the past 13 years. Approximately four million prescriptions for the drug were issued in the past year.
An estimated 8,000 patients under the age of 18 have been treated with the drug over the last 12 months.
This is despite the fact that the drug is not licensed for use in under 18s. However, doctors can prescribe Seroxat to people in this age group if they believe it is in the patient's best interest.
But the review, by the Committee on Safety of Medicines (CSM), has concluded the drug should no longer be prescribed to children.
Its experts said the risks outweighed the potential benefits. Their decision was based on new research provided by GlaxoSmithKline, the makers of Seroxat.
It showed that the drug was not effective at treating depression in under 18s.
Its studies on more than 1,000 children also suggested those on Seroxat were at least twice as likely to have suicidal thoughts or self-harm compared to children with similar mental health problems who are not taking the drug.
Glaxo submitted the information to the agency in May.
Professor Gordon Duff, chairman of the CSM, said Seroxat should no longer be prescribed to under 18s.
"Seroxat is not licensed for use in children but we know it is used in this age group outside its licensed indications where prescribers make a judgement on their own responsibility that it is the right treatment for a particular patient.
"It is therefore important that doctors, patients and parents are aware of the new advice.
"Young people under 18 years currently taking Seroxat for depression should consult their doctor."
Professor Ian Weller, who headed the review into the drug, said they would now examine whether it should continue to be prescribed to adults.
"The expert group will be examining urgently what implications, if any, these
new findings have for the use of Seroxat in adults.
This treatment has proven effective and has helped millions of people around the world
Dr Alastair Benbow,
"CSM has advised that at
present the evidence is not sufficient to confirm a causal association between SSRIs and suicidal
behaviour in adults.
"The benefits of taking Seroxat are well established and patients over 18 years and those who are benefiting from Seroxat should not be frightened into stopping their medication."
GlaxoSmithKline welcomed the decision and said adults should continue taking the drug.
Dr Alastair Benbow, its head of European Psychiatry, said: "Today's decision by the MHRA is solely concerned with the treatment of children and teenagers under 18 years with major depressive disorder.
"It is not related to the use of Seroxat by adults, where this treatment has proven effective and has helped millions of people around the world to lead fuller and more productive lives."
Richard Brook, chairman of the mental health charity, MIND welcomed the ruling.
"MIND has been concerned to ensure that the experiences of users of Seroxat
were taken seriously.
"This new evidence underlines the concerns that young patients have been voicing and MIND accept that speedy action has been taken to
address this new evidence.
"MIND strongly believes that the decision today requires us to move very quickly forward on the review of Seroxat and other SSRIs especially given the strength of concern we've heard from people taking
The Royal College of Psychiatrists welcomed the new advice from the MHRA and
said it would ensure it was passed on to its members promptly.
It said it had been concerned for many years about prescribing of
anti-depressants for under 18s and had raised the matter with the Department of Health.