Methamphetamine, or meth, is an addictive central nervous system (CNS) stimulant with limited medical value. The United States Drug Enforcement Administration (DEA) lists methamphetamine as a Schedule II drug, which means it has high abuse potential and must be prescribed by a prescription that cannot be refilled.
A 2012 National Survey on Drug Use and Health (NSDUH) reports that about 12 million Americans have tried methamphetamines. The national Monitoring the Future survey of 2014 found that 1% of eighth graders, 1% of 10th graders, and 1.9% of twelfth graders had tried methamphetamine at some time in their lives.
In the United States, methamphetamine use peaks in white men 30–40 years old; however, according the Monitoring the Future survey, the average age of first use in 2012 was 19.7 years. In the United States, methamphetamine use is highest in western states. Internationally, methamphetamine use is highest in Asia.
Methamphetamine was first synthesized in Japan in 1919 and was used as a drug therapy in asthma inhalers in the 1930s. Amphetamines of all kinds were used during World War II by both sides to increase the alertness and prolong wakefulness of soldiers. After the war, the government developed stricter regulations for the manufacture and use of amphetamines, but they remained popular among people who wanted to stay awake for long periods (e.g., students, long-haul truckers) and were commonly used by people who wanted to lose weight. In 1970, more restrictions were put on methamphetamine, so that today it is a Schedule II drug. Despite this, methamphetamine remains a popular drug of abuse.
Methamphetamine is produced illegally in many countries, including the United States, and can be synthesized with readily available materials. The drug's misuse is deemed to be a major societal problem. Methamphetamine is addictive. It goes by the street names of ice, crystal, crystal meth, speed, crank, and glass.
Methamphetamine is similar to other CNS stimulants, such as amphetamine (its parent drug), methylphenidate, and cocaine, in that it stimulates dopamine reward pathways in the brain. Consistent with its stimulant profile, methamphetamine causes increased activity and talkativeness, decreased appetite and fatigue, and a general sense of well being. Compared to amphetamine, methamphetamine is more potent and longer lasting, and it has more harmful effects on the brain. In animals, a single high dose of methamphetamine has been shown to damage nerve terminals in the dopamine-containing regions of the brain.
Methamphetamine is a white, odorless, bitter-tasting crystalline powder that easily dissolves in water or alcohol. Misuse occurs in many forms, as methamphetamine can be smoked, snorted, injected, or taken orally. When smoked or injected, methamphetamine enters the brain very rapidly and immediately produces an intense but short-lived rush that many abusers find extremely pleasurable. Snorting or oral ingestion produces euphoria—a feeling of being high—within minutes. As with other abused stimulants, methamphetamine is most often used in a binge-and-crash pattern. A “run” of repeated doses may be continued over the course of days (binge) before stopping (crash). Exhaustion occurs with repeated use of methamphetamine, involving intense fatigue and need for sleep after the stimulation phase.
Approved medical indications for the drug are the sleep disorder narcolepsy, attention deficit hyperactivity disorder (ADHD), and extreme obesity, but in each case methamphetamine is a second-line drug at best and is used only after other, less harmful drugs have failed.
The prescription drug (brand name Desoxyn) comes in the form of a small white tablet, which is orally ingested. Dosing begins at 5 mg once or twice a day and is increased weekly until the lowest effective dose is attained. Desoxyn should not be taken with other stimulants (including caffeine and decongestants) or antidepressant drugs (especially monoamine oxidase inhibitors [MAOs], but also tricyclic antidepressants). Desoxyn should not be taken by patients with glaucoma, cardiovascular disease (including hypertension and arteriosclerosis), or hyperthyroidism.
Causes and symptoms
Short-term effects of methamphetamine relate to its stimulation of the brain and the cardiovascular system. Euphoria and rush, alertness, increased physical activity, and decreased sleep and appetite occur from an increase in available dopamine in the brain. Any or all of these effects can lead to compulsive use of the drug that characterizes addiction. In addition, methamphetamine causes rapid heart beat (tachycardia), increased respiration, and increased blood pressure (hypertension), and with very high doses, increased body temperature (hyperthermia) and convulsions can occur.
Chronic use of methamphetamine can result in two hallmark features of addiction: tolerance and dependence. Tolerance to the euphoric effects in particular can prompt abusers to take higher or more frequent doses of the drug. Withdrawal symptoms in chronic users include depression, anxiety, fatigue, and an intense craving for the drug. Users who inject methamphetamine risk contracting life-threatening viruses such as HIV and hepatitis through the use of dirty needles.
With repeated use, methamphetamine can cause anxiety, insomnia, mood disturbances, confusion, hallucinations, psychosis, and violent behavior. Psychotic features sometimes emerge, such as paranoia, hallucinations, and delusions, and can last well after methamphetamine use has stopped. Stroke and weight loss are other long-term effects.
Methamphetamine use may be suspected by the symptoms described above and confirmed with a urine drug screening test
For acute intoxication accompanied by psychosis, patients may be calmed by reassurance and a quiet setting, but sometimes antipsychotic drugs or sedatives are administered. Substances that prevent absorption from the gastrointestinal tract (e.g., activated charcoal) may be used if the drug was taken orally. Additional care is given as needed (e.g., keeping the airways open, treatment of seizures.) Individual with methamphetamine intoxication may be violent, agitated, and a danger to themselves and others.
The most effective treatment for methamphetamine addiction is cognitive-behavioral intervention such as counseling but may also include family education, drug testing, and group support in a twelve-step program. The goal of these modalities is to modify the patient's thinking, expectancies, and behaviors to increase coping skills in the face of life's stressors. Contingent management is a promising behavioral intervention, where incentives are provided in exchange for staying clean and for participating in treatment. Residential programs/therapeutic communities may be helpful, particularly in more severe cases.
Antidepressant drugs such as bupropion (Wellbutrin) can be a useful treatment aid, but as of 2014, there are no FDA-approved medications specifically for the treat stimulant addiction.
Addiction is a complex disorder, and prospects for individual addicts vary widely. Chronic methamphetamine use causes changes in brain and mental function. While some effects are reversible, others are very long lasting and perhaps permanent. Methamphetamine is addictive. Relapses are common, and cravings may continue for a long time after drug use has stopped.
Teenagers are a target group for prevention strategies as adolescence and young adulthood are associated with exposure to and an inclination to experiment with drugs. Drug education and prevention programs should begin a early, and parents and teachers should be alert to the possibility of methamphetamine abuse.