MDMA or related drug dependência, including MDA is a transtorno of regulation of MDMA or related drug uso arising from repeated or continuous uso of MDMA or related drugs. The characteristic feature is a strong internal drive to uso MDMA or related drugs, which is manifested by impaired ability to control uso, increasing priority given to uso over other activities and persistence of uso despite harm or negative consequences. These experiences are often accompanied by a subjective sensation of urge or craving to uso MDMA or related drugs. Physiological features of dependência may also be present, including tolerance to the effects of MDMA or related drugs, abstinência symptoms following cessation or reduction in uso of MDMA or related drugs, or repeated uso of MDMA or pharmacologically similar substances to prevent or alleviate abstinência symptoms. The features of dependência are usually evident over a period of at least 12 months but the diagnosis may be made if MDMA or related drug uso is continuous (daily or almost daily) for at least 3 months.