The chief executive of the mental health charity Mind resigned from an expert working party on antidepressants last night in a row over doctor's prescribing unsafe doses of the drug. Richard Brook resigned accusing drug regulators of negligence in suppressing 10-year-old evidence that Seroxat was being prescribed in dangerously high quantities.

Mr Brook said the group had told the government's advisory Committee on the Safety of Medicines in October of their concerns, and this week the CSM issued "a reminder" to doctors of Seroxat's recommended dose of 20mg. Last year around 17,000 people were told by their doctors to take higher doses of the drug, whose side effects can include violent impulses and agitation.

In his letter of resignation, Mr Brook said that said crucial dosage data had been known to the Medicine and Healthcare Products Regulatory Agency, which licences drugs on advice from the CSM, since 1990.