Additional information on amphetamine-related disorders
Additional Information on Amphetamine-Related Disorders
Associated Features and Disorders
Acute Amphetamine Intoxication is sometimes associated with rambling speech, headache, transient ideas of reference, and tinnitus. During intense Amphetamine Intoxication, paranoid ideation, auditory hallucinations in a clear sensorium, and tactile hallucinations (e.g., formication or a feeling of bugs under the skin) may be experienced. Frequently, the person using the substance recognizes these symptoms as resulting from the stimulants. Extreme anger with threats or acting out of aggressive behavior may occur. Mood changes such as depression with suicidal ideation, irritability, anhedonia, emotional lability, or disturbances in attention and concentration are common, especially during withdrawal. Weight loss and other signs of malnutrition and impaired personal hygiene are often seen with sustained Amphetamine Dependence.
Amphetamine-Related Disorders and other stimulant-related disorders are often associated with Dependence on or Abuse of other substances, especially those with sedative properties (such as alcohol or benzodiazepines), which are usually taken to reduce the unpleasant, "jittery" feelings that result from stimulant drug effects.
The laboratory and physical examination findings and the mental disorders and general medical conditions that are associated with the Amphetamine-Related Disorders are generally similar to those that are associated with the Cocaine-Related Disorders (see p. 246). Urine tests for substances in this class usually remain positive for only 1-3 days, even after a "binge." Adverse pulmonary effects are seen less often than with cocaine because substances in this class are smoked fewer times per day. Seizures, HIV infection, malnutrition, gunshot or knife wounds, nosebleeds, and cardiovascular problems are often seen as presenting complaints in individuals with Amphetamine-Related Disorders. A history of childhood Conduct Disorder and adult Antisocial Personality Disorder may be associated with the later development of Amphetamine-Related Disorders.
Specific Culture, Age, and Gender Features
Amphetamine Dependence and Abuse are seen throughout all levels of society and are more common among persons between ages 18 and 30 years. Intravenous use is more common among persons from lower socioeconomic groups and has a male-to-female ratio of 3 or 4:1. The male-to-female ratio is more evenly divided among those with nonintravenous use.
Prevalence
The patterns of use of amphetamines in the general population differ between locales (e.g., with high rates in southern California) and have fluctuated greatly over the years. In the United States, general use patterns were thought to peak in the early 1980s, when more than 25% of adults reported that they had ever used one of these drugs.
Regarding more recent use, a 1996 national survey of drug use reported that around 5% of adults acknowledged ever having used "stimulant" drugs to get "high." Approximately 1% acknowledged having taken amphetamines in the prior year, and 0.4% acknowledged having taken amphetamines in the prior month. The peak prevalence of ever having used amphetamines was between ages 26 and 34 years (6%), while use in the last year was highest among 18- to 25-year-olds (2%). Some surveys have reported even higher patterns of use in some younger cohorts. A 1997 survey of high school seniors reported that 16% had ever used amphetamine-like drugs, including 10% in the prior year. It should be noted that because these surveys measured patterns of use rather than disorders, it is not known how many of those in the surveys who used amphetamines had symptoms that met the criteria for Dependence or Abuse.
Rates of Amphetamine Dependence and Abuse are more difficult to document. A national epidemiological study conducted in the United States in the early 1990s reported a 1.5% lifetime prevalence of these Amphetamine Use Disorders, including 0.14% in the past 12 months.
Course
Some individuals who develop Abuse or Dependence on amphetamines or amphetamine-like substances begin use in an attempt to control their weight. Others become introduced to these substances through the illegal market. Dependence can occur rapidly when the substance is used intravenously or smoked. Oral administration usually results in a slower progression from use to Dependence. Amphetamine Dependence is associated with two patterns of administration: episodic use or daily (or almost daily) use. In the episodic pattern, substance use is separated by days of nonuse (e.g., intense use over a weekend or on one or more weekdays). These periods of intensive high-dose use (often called "speed runs" or "binges") are often associated with intravenous use. Runs tend to terminate only when drug supplies are depleted. Chronic daily use may involve high or low doses and may occur throughout the day or be restricted to only a few hours. In chronic daily use, there are generally no wide fluctuations in dose on successive days, but there is often an increase in dose over time. Chronic use of high doses often becomes unpleasant because of sensitization and the emergence of dysphoric and other negative drug effects. The few long-term data available indicate that there is a tendency for persons who have been dependent on amphetamines to decrease or stop use after 8-10 years. This appears to result from the development of adverse mental and physical effects that emerge in association with long-term dependence. Little or no data are available on the long-term course of Abuse.
Differential Diagnosis
For a general discussion of the differential diagnosis of Substance-Related Disorders, see p. 207. Amphetamine-Induced Disorders may be characterized by symptoms (e.g., delusions) that resemble primary mental disorders (e.g., Schizophreniform Disorder or Schizophrenia versus Amphetamine-Induced Psychotic Disorder, With Delusions, With Onset During Intoxication). See p. 210 for a discussion of this differential diagnosis.
Cocaine Intoxication, Hallucinogen Intoxication, and Phencyclidine Intoxication may cause a similar clinical picture and can sometimes be distinguished from Amphetamine Intoxication only by the presence of amphetamine metabolites in a urine specimen or amphetamine in plasma. Amphetamine Dependence and Abuse should be distinguished from Cocaine, Phencyclidine, and Hallucinogen Dependence and Abuse. Amphetamine Intoxication and Amphetamine Withdrawal are distinguished from the other Amphetamine-Induced Disorders (e.g., Amphetamine-Induced Anxiety Disorder, With Onset During Intoxication) because the symptoms in these latter disorders are in excess of those usually associated with Amphetamine Intoxication or Amphetamine Withdrawal and are severe enough to warrant independent clinical attention.