 On 23 January 2013, the Advisory Council on the Misuse of Drugs (ACMD) said there was "insufficient evidence" that khat caused health problems.The ACMD said there was "no evidence" khat was directly linked with serious or organised crime, and was chewed to obtain a "mild stimulant effect much less potent than stimulant drugs, such as amphetamine".On 3 July 2013, the British Home Secretary Theresa May announced that khat was to be banned in Britain, designating it a Class C substance under the Misuse of Drugs Act 1971.