|Amphetamines are potent central nervous system stimulants and include drugs such as amphetamine, dextroamphetamine, methamphetamine (speed), and various appetite suppressants and decongestants. Although it is a central nervous system stimulant, Ritalin (methylphenidate) is chemically different from a true amphetamine; it is less potent than most amphetamines, but more potent than caffeine.|
Amphetamine use releases the brain chemical dopamine, which stimulates brain cells, enhancing mood and movement. It may also damage brain cells that contain dopamine and another nerve chemical (neurotransmitter) called serotonin. Over time, levels of dopamine decrease. This may cause stiffness, tremor, and other symptoms similar to those in Parkinson's disease.
As with any addiction process, abuse and dependence are defined by continued use in the face of negative consequences. These consequences may fall into one or more of the following areas: physical and psychological health, occupational functioning, legal problems, interpersonal relationships, and financial affairs. A useful definition of dependence is loss of control over when and how much of the substance is used. The diagnosis of abuse is made when the use of the substance is recurrent despite adverse consequences to the person. The diagnosis of amphetamine abuse and dependence is based on criteria listed in the DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision). Amphetamine dependence occurs when an individual uses one or more of the amphetamine substances in a maladaptive way resulting in at least three of the following symptoms: a need for increased amounts of amphetamines to achieve the desired subjective effect (tolerance); the presence of withdrawal symptoms such as depression, fatigue, insomnia or hypersomnia, increased appetite, or agitation; using amphetamines in larger amounts or for longer duration; a persistent, unsuccessful attempt to control use of the substance; increased amount of time spent using or obtaining amphetamines; giving up important activities in deference to the use of amphetamines; and continued amphetamine use despite related physical, emotional, occupational, legal, or relational difficulties.
These substances can be taken orally, inhaled through the nose, smoked, or injected intravenously. The effects may appear in 30 to 40 minutes and last for 4 to 8 hours. Amphetamine use may result in feelings of being high or elated (euphoria), talkativeness, hyperactivity, restlessness, heightened awareness of threatening or other stimuli (hypervigilance), anxiety, tension, grandiosity, anger, and impaired judgment. Other effects may include decreased appetite, more rapid breathing, increased heart rate and blood pressure, fever (hyperthermia), confusion, tremors, seizures, suspiciousness (paranoia), and aggressive behavior.
Many individuals begin use of amphetamines to lose weight while others use amphetamines for some types of inadvertent self-medication or for recreational purposes. MDMA, a methamphetamine-based recreational stimulant popularly called ecstasy, generates effects lasting 3 to 6 hours. It's often used as a "club drug" by dancers seeking the sense of rapture, excitement, and social disinhibition it produces.
Smoked or injected amphetamine more commonly leads to dependence than does the oral form. Individuals who have used daily for 8 to 10 years tend to decrease or stop use because of adverse side effects such as depression, sleep disturbances, malnutrition, or cardiovascular complications including chronic chest pain or irregular heart rate.
As methamphetamine can be easily manufactured illegally from store-bought materials, it is the most prevalent synthetic drug manufactured in the US ("Methamphetamine").
Risk: Amphetamine use is most prevalent from ages 18 to 30 (16% in one survey). Intravenous use is more common in lower socio-economic groups and is 3 to 4 times more common in men than women. Approximately equal numbers of men and women use amphetamines by other routes. Use of these agents is also associated with an increased risk of heart attack, irregular heart rhythms, and stroke.
In 1997, there were more than 50,000 hospital admissions in the US for treatment of methamphetamine abuse or its complications, accounting for almost 4% of all treatment admissions. There is higher use in some locales such as Southern California (DSM-IV-TR 229). A pattern of abuse may lead to fever and seizures which may result in death.
Incidence and Prevalence: In 2002, more than 10 million people had tried MDMA (ecstasy - the most potent form of methamphetamine) at least once in their lifetime (Volkow), an increase from the 6.4 million reporting use in 2000. The number of current users in 2002 was estimated to be 676,000. The initiation of ecstasy use in the US has been rising steadily since 1992, with 1.8 million new users in 2001 ("MDMA Abuse").