Methamphetamine is a stimulant drug that has
been around for decades. Its popularity has waxed
and waned over the years, but its use seems
to be increasing in many parts of the United
States and in several population subgroups.
Methamphetamine is very addictive, it can be
injected, and it can increase sexual arousal while
reducing inhibitions. Because of these attributes,
public health officials are concerned that users
may be putting themselves at increased risk of
acquiring or transmitting HIV infection―a valid
concern, considering that methamphetamine use
has been linked with increased numbers of HIV
infections in some populations .
There is a growing body of research on
methamphetamine use among men who have sex
with men (MSM). Overall, assessments show that
MSM who use methamphetamine may increase
their sexual risk factors (for example, they may use
condoms less often, have more sex partners, and
may engage in practices that elevate their risk for
HIV infection, such as unprotected receptive anal
sex) and perhaps their HIV-related drug-use risk
factors (for example, injecting methamphetamine
instead of smoking or snorting it) .
MSM are not the only group with risk factors
related to methamphetamine use. Evidence shows
that heterosexual adults and adolescents under the
influence of methamphetamine may also engage in
practices that increase their risk for HIV infection
and other sexually transmitted diseases (STDs) .
However, among MSM, the baseline prevalence of
infections (such as HIV) and risk behaviors (such
as number of partners and anal sex) tends to be
higher, resulting in greater risk for transmission. Methamphetamine users may exchange sex for
money or drugs, creating another risk factor for
acquiring and transmitting HIV .
What is becoming clear is that the use of
methamphetamine can contribute to sexual risk
behaviors, regardless of the sexual orientation
of the user. Current data indicate a strong link
between methamphetamine use and sexual risk
among MSM, and perhaps among heterosexual
adults and youth.
The following are facts about methamphetamine,
its effects on the body, and research showing its
role in increasing behaviors that put persons at risk
of acquiring or transmitting HIV infection.
Methamphetamine is a central nervous system
stimulant categorized by the U.S. Food and Drug
Administration as a Schedule II amphetamine,
which means it has a high potential for abuse and
for psychological or physical dependence. There
are numerous slang names for methamphetamine,
some of which are regional or group-specific. The
most common are meth, crystal meth, Tina, ice,
and glass. Methamphetamine is smoked, injected,
snorted, swallowed, or inserted into the anus .
How Methamphetamine Is Produced
Methamphetamine can be produced through a
series of fairly simple chemical steps involving
a common decongestant―ephedrine or pseudoephedrine―
in combination with products such
as iodine crystals, battery acid, red phosphorous,
and anhydrous ammonia. It can be formulated as a liquid, a powder, a waxy solid (glass), or a clear
Methamphetamine Use in the United
According to the Substance Abuse and Mental
Health Services Administration (SAMHSA), in
- an estimated 12 million persons aged
12 and older (4.9% of US persons aged 12
or older) had used methamphetamine at
least once in their lifetime
- 1.4 million persons aged 12 or older (0.6% of
the US population) had used methamphetamine
during the past year
- 600,000 (0.2% of the US population) had used
it during the past month .
SAMHSA estimated that from 1993 through
2003, the rate of admissions for the treatment
of methamphetamine or amphetamine abuse
increased from 13 to 56 admissions per 100,000
for people aged 12 or older .
Studies show a higher prevalence of
methamphetamine use among MSM than among
the general population. For example, in a study of
urban, young MSM (aged 15-22 years), conducted
during 1994–1998, 20% of the participants
reported having used methamphetamine during
the past 6 months . A 2001 study found
that 15% of MSM in San Francisco had used
methamphetamine during their most recent
anal sex (within the past 3 months)―making
methamphetamine use third only to the prevalence
of alcohol and marijuana use .
The current increase (since the early 1990s)
of methamphetamine use began in the western
United States. However by the mid-2000s, its use
had become a nationwide concern. The National
Clandestine Laboratory Database, which includes
the number of clandestine labs seized, showed an
increase in the number of lab seizures in almost every state from 2000 through 2005 . As of
2004, the rates of methamphetamine use were
particularly high in the western states: 12 states,
including California, Nevada, Wyoming, and
Montana, ranked in the top third of states in terms
of methamphetamine use during the past year .
Lab seizures and restrictions on purchasing
ingredients have reduced the production of
methamphetamine in the United States.
The Effects of Methamphetamine Use
As a central nervous system stimulant,
methamphetamine directly affects the brain and
the spinal cord by interfering with the normal
release and uptake of neurotransmitters (chemicals
that nerve and brain cells produce to communicate
with each other). Dopamine is the primary
neurotransmitter affected by methamphetamine,
but norepinephrine and epinephrine are also
The use of methamphetamine causes the release
of large quantities of neurotransmitters. The
neurotransmitters, in turn, cause increased heart
rate and blood pressure levels and produce
sensations of pleasure, self-confidence, energy,
and alertness. They also suppress the appetite
and enhance sexual arousal. Users may report
sleeplessness, talkativeness, teeth grinding,
increased body temperature, and compulsive
behavior, such as skin picking.
Long-term use can cause physical symptoms
(decayed teeth, weight loss, skin lesions, stroke,
and heart attack) as well as mental symptoms
(paranoia, hallucinations, anxiety, and irritability)
and behavioral symptoms (aggressiveness,
violence, and isolation).
The long-term use of methamphetamine
can lead to reduced levels of dopamine and
other neurotransmitters, making the user
crave methamphetamine to raise dopamine
levels. Because bingeing on the drug depletes neurotransmitter stores, coming down from
the high is often described as a “crash,” which
includes a phase of depression. Additional doses of
methamphetamine are often used to alleviate these
negative feelings. This cycle can lead to addiction,
which can be very difficult to overcome.
Because methamphetamine use can cause
impotence at the same time that it is increasing
libido, some MSM may use erectile dysfunction
medications and may then engage in unprotected
receptive or insertive anal sex while under the
influence of the drugs .
How Methamphetamine Compares
with Amphetamines or Cocaine
Changes in specific parts of the brain of
methamphetamine users are similar to those of
cocaine and other substance users; however,
methamphetamine, amphetamines, and cocaine
differ in some ways.
For example, compared with amphetamines,
methamphetamine has longer lasting and
more toxic effects. Methamphetamine is also
stronger and longer lasting than cocaine.
Methamphetamine, compared with cocaine,
causes a more than 3-fold release of dopamine in
the brain and has a half-life (the amount of time
necessary for half of the drug to be metabolized)
of 12 hours, compared with cocaine’s half-life
of 1 hour. If smoked, it can produce a high for
8–24 hours; smoking cocaine produces a high
for approximately 20–30 minutes . Because
its effects last longer and it is less expensive
than cocaine, methamphetamine is attractive to
many populations, including young people, who
sometimes refer to it as “poor man’s cocaine.”
The Methamphetamine User
There is no typical methamphetamine user. The
drug is used by people of different ages and
races, in all parts of the country, and for different
reasons. However, some trends have been noted in
the United States.
- Age: Many methamphetamine users are young.
Because it is cheaper and longer lasting than
cocaine, methamphetamine is becoming
popular with persons in their teens and early
20s [10, 11]. The average age at first use was
18.9 years in 2002, 20.4 years in 2003, and
22.1 years in 2004 . The highest rate of
methamphetamine use during the past year was
that for young adults aged 18 to 25, followed
by youth aged 12 to 17, and then adults aged
26 or older .
- Sex: Among all persons 12 years of age or
older, the rate of use during the past year was
about the same for males and females (0.7%
and 0.5%, respectively) .
- Race/ethnicity: The largest numbers
methamphetamine users are white. However,
the highest rates of methamphetamine use
during the past year were those for Native
Hawaiians or other Pacific Islanders (2.2%),
American Indians or Alaska Natives (1.7%),
and person who reported 2 or more races
(1.9%). Past-year use among whites (0.7%)
and Hispanics (0.5%) was higher than among
blacks (including African Americans) (0.2%). .
- MSM: According to data from the 2004
CDC National HIV Behavioral Surveillance
System, overall, a higher percentage of MSM methamphetamine users compared
to non-users were white (50.4% vs. 43.5%
- Rural users: Many methamphetamine
users in rural areas are white, working class,
heterosexual young adults . Trends in
rural areas show that increasing numbers of
Latinos, Native Americans and youth are using
methamphetamine. Rural users, compared with
urban users, are more likely to be heterosexual
Reasons For Methamphetamine Use
The reasons for using methamphetamine vary.
- Males and females have reported using
methamphetamine for increased energy and productivity, its low cost, self-medication
for depression or attention deficits, and the
euphoric high [13,14].
- Males have reported using methamphetamine
for economic reasons, (selling the drug,
increased energy to work multiple jobs)
and sexual reasons (enhanced libido and
endurance) [11, 14].
- A study of HIV-positive MSM who use
methamphetamine found that the most
frequently reported motivation for use was to
enhance sexual pleasure (reported by nearly
90% of respondents) . Other reasons
included self-medication of negative feelings
associated with HIV-positive serostatus.
A similar study of HIV-negative heterosexual
adults found that the primary motivations for
methamphetamine use were to get high, to get
more energy, and to party .
- Females reported using methamphetamine to
control weight and to combat fatigue .
- The culture of methamphetamine use provides
a social network―a community―for persons
who feel like outsiders .
Methamphetamine Use and HIV Risk
A growing body of research supports the
relationship between methamphetamine use
by MSM and heterosexual populations and an
increase in behaviors (sexual and those related to
injection drug use) that can put the user at risk for
- A survey of users of noninjection drugs,
conducted in California during the mid-1990s,
showed that heterosexual persons and MSM
who reported using methamphetamine also
had more sex partners, were less likely to use a
condom, and were more likely to exchange sex
for money or drugs, have sex with an injection
drug user, or to have a history of STD―all risk
factors for HIV transmission .
- A qualitative study of gay and bisexual men in
Seattle (Washington) and San Jose (California),
conducted during 1997–2001, revealed a high
prevalence of club drugs (methamphetamine,
ecstasy, ketamine, and GHB [gamma hydroxyl
butyrate]) in tandem with unsafe sex practices.
Many of the respondents reported that they
already had HIV infection or AIDS and that
they “medicated” their symptoms through their
drug use. Respondents reported engaging in
unprotected sex as well as trading sex for drugs
- A 2001 study conducted among gay and
bisexual men in the San Francisco Bay
Area showed that of MSM who participated
in circuit party weekends, those who used
methamphetamine were more than twice as
likely to have unprotected anal sex during that
weekend with a partner whose HIV status was
unknown or different from theirs .
- According to a 1998 study conducted at
publicly funded HIV testing sites in California,
HIV-positive MSM may be more likely than
HIV-negative MSM to use methamphetamine,
and some MSM methamphetamine users may
be more likely than other methamphetamine
users to use it during sex .
- An analysis of data of heterosexual men,
performed by the California Department of
Health Services during 2001–2003 determined
that recent methamphetamine use was
associated with high-risk sexual behaviors,
including anal intercourse, sex with an
injection drug user, and sex with a casual or an
anonymous female partner .
- In California, 9.5% of primary and secondary
syphilis cases in heterosexual men during
2004 were cases in men with a history of
methamphetamine use, continuing a trend of
increases in syphilis cases, from 3.1% in 2001,
6.4% in 2002, and 7.3% in 2003 . Syphilis
infection is a marker for unprotected sex, a risk
factor for HIV infection.
- During a gonorrhea outbreak in 6 central
California counties in 2004, substantial proportions of heterosexual men (38%) and
women (28%) reported methamphetamine use,
particularly when compared with MSM (8%)
. Like syphilis, gonorrhea infection is a
marker for unprotected sex, a risk factor for
- Some evidence suggests that the use
of methamphetamine (not injected) by
heterosexual men and women is associated
with unprotected vaginal sex and with a higher
number of sex partners during the past 12
In addition to increasing sexual risk factors,
methamphetamine use increases the risk for
HIV transmission when the drug is injected. For
example, women reported being injected with
methamphetamine by sex partners, often with
a shared syringe . According to a Colorado
study, people who injected methamphetamine
more frequently shared syringes during a
methamphetamine binge .
Specific Ways Methamphetamine
Use Negatively Affects Thinking and
- Methamphetamine use may impair the ability
or the desire to be safe, both sexually and when
injecting drugs. That impairment, in turn, may
lead to experimentation with riskier behaviors in
- Methamphetamine may dry mucosa, which
may lead to more chafing and abrasions, which,
in turn, could provide an entry for HIV during
- Methamphetamine use is associated with sexual
practices that may increase the likelihood of HIV
and other STD transmission (e.g., long duration,
leading to chafing or sores; multiple partners;
lack of inhibition; low level of condom use).
- Methamphetamine use may cause mental
confusion and impair the ability to take
medications that have been prescribed for HIV
infection or other conditions.
Public Health Implications
Methamphetamine use is a public health issue.
There is a need for a broad approach in addressing
methamphetamine use and risk for infection
with HIV and other STDs―one that includes
heterosexual adults and adolescents as well as
MSM. HIV and STD prevention and treatment
programs could be enhanced to include assessment
for methamphetamine use, with referrals to
methamphetamine treatment, primary testing, and
sexual health promotion.
- Buchacz K, McFarland W, Kellogg TA, et al.
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