The symptoms of amphetamine psychosis include auditory and visual hallucinations, grandiosity, delusions of persecution, and delusions of reference concurrent with both clear consciousness and prominent extreme agitation. A Japanese study of recovery from methamphetamine psychosis reported a 64% recovery rate within 10 days rising to an 82% recovery rate at 30 days after methamphetamine cessation. However it has been suggested that around 5–15% of users fail to make a complete recovery in the long term. Furthermore, even at a small dose, the psychosis can be quickly reestablished. Psychosocial stress has been found to be an independent risk factor for psychosis relapse even without further substituted amphetamine use in certain cases.The symptoms of acute amphetamine psychosis are very similar to those of the acute phase of schizophrenia although in amphetamine psychosis visual hallucinations are more common and thought disorder is rare. Amphetamine psychosis may be purely related to high drug usage, or high drug usage may trigger an underlying vulnerability to schizophrenia. There is some evidence that vulnerability to amphetamine psychosis and schizophrenia may be genetically related. Relatives of methamphetamine users with a history of amphetamine psychosis are five times more likely to have been diagnosed with schizophrenia than relatives of methamphetamine users without a history of amphetamine psychosis.
Stimulant psychosis is a mental disorder characterized by psychotic symptoms (such as hallucinations, paranoid ideation, delusions, disorganized thinking, grossly disorganized behaviour) which involves and typically occurs following an overdose or several day binge on psychostimulants; however, it has also been reported to occur in approximately 0.1% of individuals, within the first several weeks after starting amphetamine or methylphenidate therapy. Methamphetamine psychosis, or long-term effects of stimulant use in the brain (at the molecular level), depend upon genetics and may persist for some time.The most common causative agents are substituted amphetamines, including substituted cathinones, as well as certain dopamine reuptake inhibitors such as cocaine and phenidates. Signs and symptoms
The symptoms of stimulant psychosis vary depending on the drug ingested, but generally involve the symptoms of organic psychosis such as hallucinations, delusions, or paranoia. Other symptoms may include mania, erratic behavior, agitation and/or aggression. Cause
Substituted amphetamines
Drugs in the class of amphetamines, or substituted amphetamines, are known to induce "amphetamine psychosis" typically when chronically abused or used in high doses. In an Australian study of 309 active methamphetamine users, 18% had experienced a clinical level psychosis in the past year. Commonly abused amphetamines include methamphetamine, MDMA, 4-FA, as well as substituted cathinones like a-PVP, MDPV, and mephedrone, though a large number of other closely related compounds have been recently synthesized. Methylphenidate is sometimes incorrectly included in this class, although it is nonetheless still capable of producing stimulant psychosis.