Amphetamine-Related Psychiatric Disorders

Excerpt

Amphetamines, such as methamphetamine and 3,4-methylenedioxymethamphetamine (MDMA), belong to a class of compounds called phenethylamines which induce catecholaminergic effects in the CNS and peripheral circulation. Amphetamine was first manufactured in 1893 to treat asthma and upper respiratory congestion, but indications and usage in the medical field have increased over the last century. Today, amphetamines are clinically used to treat short-term obesity, narcolepsy, and attention deficit disorder with hyperactivity. Recreational use of amphetamines has reached epidemic proportions in Asia, Australasia, and the United States. The majority of illegal amphetamines in North America are produced in rural areas of Mexico and the United States in clandestine labs. Amphetamines can be easily manufactured using common household materials, including acetone, red phosphorus, sodium hydroxide, sulfuric acid, ammonia, toluene, along with over-the-counter medicines, ephedrine, and pseudoephedrine.

The routes of amphetamine administration may be inhalation, intravenous, intramuscular, or transmucosal (oral/nasal). Peak plasma levels can range from 5 to 10 minutes via intravenous administration and up to 2 to 3 hours if taken transmucosal. Symptoms typically last hours to days, based on dosage and strength, and dissipate once the drug is eliminated from the body. Given the acute symptoms associated with amphetamine intoxication, it is difficult for the clinician to distinguish amphetamine-associated psychosis from the acute psychosis of a primary mental disorder. Most agree that psychosis following amphetamine use is characterized by persecutory delusions, visual hallucinations, and symptoms resembling acute psychosis most commonly observed in schizophrenia.

There is also a clear pattern of high dosage and daily usage correlating with higher risks of substance-induced psychosis. Amphetamines impair the cognitive thought process and subsequently precede acute psychosis. This suggests that continued impairment due to amphetamine use is a precursor to psychosis.