The European Medicines Agency (EMEA) is recommending doctors do not prescribe the anti-obesity drug Acomplia.
The drug watchdog has said that the benefits from Acomplia, a brand name for the drug rimonabant, "no longer outweigh its risks".
The agency has said the marketing license should be suspended after it was told patients who took the drug were twice as likely to suffer from psychiatric disorders, such as depression, anxiety and aggression.
Sanofi-aventis, which manufactures Acomplia, has agreed to comply with the recommendation immediately, although it needs to be rubber-stamped by the European Commission.
Acomplia has been EU-authorised since June 2006 to be used alongside diet and exercise to treat obese or overweight patients and has been "moderately effective".
The EMEA said the committee had assessed information on the benefits and risks of the drug and looked at data from studies.
Patients who already take the drug will have their treatment reviewed and have been advised to contact their doctor or pharmacist.