The MHRA has decided not to bring a criminal prosecution case against GSK following a four year investigation into anti-depressant Seroxat, and has separately pledged to strengthen drug safety laws.The potential case hinged on whether or not GSK had failed to inform the MHRA quickly enough of information it held on the safety of Seroxat for patients under 18.The drugs firm gave the MHRA data from clinical trials in May 2003, confirming that patients under 18 had a higher risk of suicidal behaviour if treated with Seroxat, compared with a placebo.The drug was not approved for under 18s, and the MHRA  investigation found legislation at the time did not require companies to inform the agency of safety information when the drug was tested outside its licensed indications.Professor Kent Woods, MHRA chief executive, said: “I remain concerned that GSK could and should have reported this information earlier than they did."He said there were weaknesses in the drug safety legislation at the time, and despite subsequent improvements, immediate steps would be taken to ensure the law is strengthened further.GSK rejected any claims that it had withheld information.Dr Alastair Benbow, medical director for GSK Europe, said: “We firmly believe we acted properly and responsibly.”MHRA websiteGSK website