The euphoric or pleasure-giving use of khat (qat) is steadily increasing. Some authorities consider that its continuous consumption does much harm from physiological, psychological and social points of view - particularly the latter, since the product is expensive and the habitual consumer spends a large part of his income on it, with consequent neglect of his family and job. Effects of khat are similar to those produced by the amphetamine group but milder. Physical dependence and tolerance do not occur. Recognition of this problem has arisen only in recent years. Khat is not covered by the schedules annexed to international conventions on narcotic drugs or by the Convention on Psychotropic Substances.
Some urban Yemenis spend up to one third of their income on khat.