Methamphetamine Abuse: Consequences and Treatment

Methamphetamine (MA) abuse is not a new problem in the United States, but the current epidemic is more widespread and presents with more pernicious consequences than in the past. MA, frequently called "speed," "crystal," "crank," "ice," or "tina," is a potent psychostimulant that can be swallowed in pill form or administered via intranasal, intravenous, or smoking route.

Epidemiologic data on the extent and consequences of MA use among increasingly involved populations—women, men who have sex with men, rural residents, and youths—indicate a need for additional efforts to effectively treat persons who use MA and those with problems related to MA use. Recent research has influenced the way we think about MA and the related medical consequences of its use. For example, neuroimaging research and new information on the cellular mechanisms of MA's action indicate new targets for the development of pharmacotherapies. While pharmacotherapy research is still in a formative stage, behavioral therapies that have been developed for the treatment of stimulant use disorders have considerable empiric support.

In the late 1960s, MA became known as a dangerous drug, creating substantial health threats to persons who used it and prompting the drug prevention slogan "speed kills." During the late 1970s and early 1980s, MA use in the United States was, for the most part, limited to several cities in California (primarily San Francisco and San Diego), since the primary manufacturers and suppliers of MA at the time were members of Hells Angels and other motorcycle gangs that were headquartered in California.¹

In the mid-1980s, MA use escalated dramatically in Honolulu as "ice," a smokable form of the drug, was imported to the island from the Philippines.² In the 1990s, MA spread throughout the western states and began to surface in substantial amounts in the Midwest (eg, Iowa and Missouri).³

Today, MA has emerged as one of the most dangerous "homegrown" drugs in the country, and its use and dependence pose significant public health challenges.⁴ MA is the most widely used illicit drug in the world after cannabis,⁵ and it has become established as the most dominant drug problem in many western and midwestern states, severely impacting rural and suburban areas, as well as small to mid-sized cities.

MA's availability and use have migrated from the western states to mid-America and the southeastern states.⁶ In 2003, 14 states cited more admissions to substance abuse treatment programs resulting from MA use than from heroin and cocaine use combined; nationally, admissions related to MA use increased 10% between 2002 and 2003 (from 105,754 to 116,604).⁷

Women use MA at rates almost equal to those of men. While the use of other major illicit drugs is characterized by ratios such as 3:1 (heroin) or 2:1 (cocaine) for men to women, in many large data sets, the ratio for persons who use MA approaches 1:1. Surveys among women suggest that they are more likely than men to be attracted to MA for reasons such as weight loss and for the control of symptoms of depression. More than 70% of women who use MA report histories of physical and sexual abuse, and women are more likely than men to present for treatment of MA abuse with greater psychological distress.⁸

MA use is also associated with high-risk sexual behaviors, which has been shown to be a major factor in HIV transmission among men who have sex with men.⁹ Research by Shoptaw and colleagues¹⁰ showed that MA use poses the biggest threat of producing a renewed spread of HIV in the gay community because of the increase in high-risk sexual behaviors. The researchers have developed treatment programs for this group that have shown the successful treatment of MA dependence to be an extremely effective HIV prevention strategy.

There appears to be an increase in MA use among adolescents in some parts of the country, particularly on the West Coast. Phoenix House, a large treatment center for adolescents in Southern California, reported that MA use accounted for almost half of the center's admissions in 2005¹¹; there was particular concern in the center regarding MA use among young women.

In another report on MA use among adolescents, 63% of girls who were admitted to substance abuse treatment received a primary diagnosis of MA abuse/dependence while only 36% of boys received MA abuse/dependence as a primary diagnosis.¹²

The euphoric feelings (described as a "high" or "rush") that accompany the use of MA appear to be the result of dopamine(Drug information on dopamine) release in the reward/pleasure centers of the brain. The timing and intensity of such stimulant effects depend largely on the drug's route of administration. The effects of the drug are almost instantaneous when it is smoked or injected.

Conversely, it takes about 5 minutes after snorting MA or 20 minutes after ingesting it for the onset of such effects to occur. The half-life of MA is about 8 to 12 hours, and the acute effects of MA occur during this period.

Immediate physiological changes associated with MA use are similar to those that are produced in the fight-or-flight response: that is, increased blood pressure, body temperature, heart rate, and respiration rate. Even small doses of MA can increase wakefulness, attention, and physical activity and can decrease fatigue and appetite.

Negative physical effects of MA use typically include hypertension, tachycardia, headaches, cardiac arrhythmia, and nausea; the psychological impact is manifested by increased anxiety, insomnia, aggressive and violent tendencies, paranoia, and visual and auditory hallucinations. High doses can elevate body temperature to dangerous and sometimes lethal levels, causing convulsions, coma, stroke, vegetative states, and death.

In persons who use MA for prolonged periods, tolerance for the drug frequently develops, along with escalating dosage levels and dependence. Persons who chronically use MA can be anxious and exhibit violent behavior, confusion, and insomnia, which is a result of the direct effects of the drug plus the consequences associated with sleep deprivation, since persons who use MA often report sleeplessness for days and even weeks. When they are in a state of prolonged MA use and sleep deprivation, users commonly experience a number of psychotic features, including paranoia, auditory hallucinations, mood disturbances, and delusions. One of the most regularly reported features associated with MA use is "formication," the sensation of insects creeping on the skin. The paranoia that accompanies MA use can result in homicidal or suicidal thoughts.

In a recent sample of MA users who entered treatment in the Midwest, Hawaii, and California, the rate of hepatitis C was 22%. Of those administering MA via injection, 45% tested positive for hepatitis C.¹³ Clearly, there needs to be a stronger effort to inform persons about behaviors that expose them to hepatitis C (through blood-to-blood transfers) and to treat and prevent MA use and abuse. See the Table for a summary of MA's adverse effects.