European drug regulators are concerned that Prozac, like its sister antidepressants, is unsafe for children, contrary to UK advice.
More safety checks are needed say experts
The Committee for Medicinal Products for Human Use (CHMP) reviewed all of the available data.
It said there was an increased risk of suicidal behaviour and thoughts with all antidepressants known as Selective Serotonin Reuptake Inhibitors (SSRIs).
UK regulators say the benefits of Prozac in under 18s outweigh any risk.
The Medicines and Healthcare products Regulatory Agency issued this advice last year after its own review.
It said other SSRIs were too risky for children.
This week, the National Institute for Clinical Excellence called on doctors to exercise more caution in prescribing antidepressants.
The CHMP will now inform the European Commission that there are public health concerns in relation to the safe use of these drugs in children and adolescents with depression, anxiety and related conditions, irrespective of the therapeutic indication.
It will recommend further safety investigations are carried out.
In the meantime, SSRIs should generally not be used in children or adolescents, it said, but it warned against anyone stopping their treatment without first seeking medical advice.
"Patients or parents who have any concerns about the medication are advised to consult the treating doctor at the next available opportunity to discuss treatment," it said.
A spokeswoman from the Department of Health said: "The MHRA has acted faster and gone further than any other regulator in the world to take action on emerging safety issues relating to SSRIs.
"After a thorough review of the data, the UK advised that the treatment of childhood depression with any SSRI except Prozac should not continue.
"The UK is the only country in Europe to have issued comprehensive advice about the use of all SSRIs in children."
Eli Lilly, the makers of Prozac, has said that while the use of anti-depressants can increase the risk of suicidal behaviour in children, there have been no reported deaths.
A spokesman said: "However, when people with depression are left untreated, 15% will actually commit suicide.
"Lilly believes medication should be prescribed only after a careful diagnosis is made, and continued only if it clearly benefits the child. Because suicidal thinking is an inherent part of depression, we believe careful monitoring of patients is very important. "
The company has also stressed it has never marketed Prozac for use in paediatric patients.
Growing numbers of youngsters in the UK are being prescribed antidepressants, according to authors of a study in the British Medical Journal this week.
At the end of 2003 more than 50,000 children were being given the medication, with more than 170,000 prescriptions for antidepressants issued to under-18s in
the UK, they said.
Lead researcher Sami Timimi, a consultant child and adolescent psychiatrist in Lincolnshire, said research suggested that SSRIs were largely ineffective and may be dangerous in young children.
He said there should be more emphasis on non-medical treatments for children with depression.
Marjorie Wallace, chief executive of the mental health charity SANE said: "What we need is more research into the effects of medications on the developing brain, so that safer medical treatments can be offered, as well as an urgent increase in the numbers of therapists for young people who are ill and their families."