The past decade has seen a marked increase in the popularity of ATS use, particularly methamphetamine, within East Asia,and the Pacific region. In Malaysia, the National Anti Drug Agency has identified 8,870 addicts (from January till August 2008) out of which 1,126 was ATS dependence. During the same period, the police have arrested 46,388 people under the Dangerous Drug Act 1952. They also has seize 283kg of syabu, 545kg of ecstacy powder, 66194 tablets of esctacy pills and 222,376 tablets of yaba pills from Jan till August this year. The occurrence of psychosis arising from the use of ATS was first reported in the late 1930's. With growing ATS use, particularly methamphetamine, ATS-induced psychosis has become a major impact on public health.Symptoms of ATS-induced psychosis: Methamphetamine use produces a variety of effects, ranging from irritability, to physical aggression, hyperawareness, hypervigilance, and psychomotor agitation. Repeated or high-dose use of the stimulant can cause drug-induced psychosis resembling paranoid schizophrenia, characterized by hallucinations, delusions and thought disorders. When used in long term, methamphetamine may lead to development of psychiatric symptoms due to dopamine depletion in the striatum. The most common lifetime psychotic symptoms among methamphetamine psychotic patients - as reported in a cross-country study involving Australia, Japan, the Philippines and Thailand - are persecutory delusion, auditory hallucinations, strange or unusual beliefs and thought reading. Those patients were also reported to suffer from impaired speech, psychomotor retardation, depression and anxiety. An ATS psychosis can be distinguished from primary psychotic disorders by time. In ATS-induced psychosis symptoms usually resolve after the drug is discontinued. If symptoms do not resolve within 2 weeks after cessation of stimulant use, a primary psychiatric disorder should be suspected. When compared with other stimulants, such as cocaine, psychosis is induced more commonly by ATS, possibly due to the longer duration of action produced by amphetamines.For example, while smoking cocaine produces a high that lasts for 20-30 minutes, smoking methamphetamine produces a high that lasts 8-24 hours. Other symptoms of ATS-induced psychosis reported include affective blunting,(6) violent behavior, and self-mutilation and self-injurious behavior.