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Drugs and diseases reference index

Diseases reference index «Drug abuse»

Drug abuse

Drug abuse is the use of illegal drugs, or the misuse of prescription or over-the-counter drugs for at least a year with negative consequences.

See also:

  • Drug abuse and dependence
  • Drug abuse first aid


MARIJUANA (also called "grass," "pot," "reefer," "joint," "hashish," "cannabis," "weed," and "Mary Jane")

About 2 in 5 Americans have used marijuana at least once. About 10% of the population uses it on a regular basis.

The source of marijuana is the hemp plant (cannabis sativa). The active ingredients are THC (delta-9-tetrahydrocannabinol) and other cannabinoids, which are found in the leaves and flowering shoots of the plant.

Hashish is a substance taken from the tops of female plants. It contains the highest amount of THC.

The drug dose in marijuana varies greatly depending on how it is prepared.

You may feel the effects of marijuana within seconds to several minutes after breathing in the smoke (from a joint or pipe), or within 30 - 60 minutes after eating foods containing marijuana, such as "hash brownies."

  • The main effects of marijuana are on behavior, because the drug acts on the central nervous system (CNS). Marijuana became popular because it gives people a feeling of joy (euphoria), relaxation, and increased sensations of sight, hearing, and taste with low to moderate doses.
  • Most users also report an increase in their appetite ("the munchies").

Unpleasant effects that may occur include:

  • Acute panic reactions or severe paranoia
  • Changed body image
  • Lack of orientation
  • Trouble telling oneself from others

Other troubling side effects may include:

  • Some cases of severe delirium, seeing or hearing things that aren't there (hallucinations), and violence have also been reported. In such cases, marijuana may have been laced with another drug, such as PCP.
  • Marijuana has specific effects that may decrease your ability to perform tasks that require a lot of coordination (such as driving a car). It affects visual tracking and prolongs the sense of time. It also decreases the desire to complete tasks.
  • The drug can affect learning because it can reduce your ability to concentrate and pay attention.

Other marijuana effects may include:

  • Airway (bronchial) irritation leading to narrowing of the airways (bronchoconstriction) or airway spasms (bronchospasm)
  • Bloodshot eyes
  • Increased heart rate and blood pressure
  • Pharyngitis, sinusitis, bronchitis, and asthma in heavy users
  • Possible serious effects on the immune system
  • Widening of the airways (bronchodilation)

Regular users may have withdrawal effects when they stop marijuana use. These may include:

  • Agitation
  • Anxiety
  • Insomnia
  • Irritability

Because the substance formed when the body breaks down marijuana may be stored in the body's fat tissue, heavy users may show evidence of marijuana use in urine tests for up to 1 month after stopping the drug.

The active substance in cannabis is believed to have medical properties, which include:

  • Relieving chronic pain and spasticity
  • Stimulating appetite in patients with AIDS or who have undergone chemotherapy
  • Treating glaucoma
  • Treating nausea caused by chemotherapy in cancer patients

THC has been approved by the Food and Drug Administration for these purposes.

The use of whole marijuana remains very controversial. More than 13 states have laws to provide legal sanction for the medical use of marijuana. The federal government still considers whole marijuana to be a controlled substance that is illegal, even for medical use.

PHENCYCLIDINE (PCP, "angel dust")

It is difficult to estimate the current use of phencyclidine in the United States, because many people do not know that they have taken it. Other illegal substances (such as marijuana) can be laced with PCP without the user being aware of it.

PCP can be made easily and cheaply by anyone who knows organic chemistry. This makes it a prime drug for the illegal drug industry. It is available illegally as a white powder that can be dissolved in either alcohol or water.

PCP may be taken in different ways. How fast it affects the user depends on how it is taken.

  • If dissolved, PCP may be taken through a vein ("shot up") and its effects begin within seconds.
  • Sprinkled over dried parsley, oregano, or marijuana leaves, it can be smoked. The effects begin within 2 - 5 minutes, peaking at 15 - 30 minutes.
  • Taken by mouth, in pill form, or mixed with food or drinks, PCP's effects usually start within 30 minutes. The effects tend to peak in about 2 - 5 hours.

Different doses of PCP will cause different effects:

  • Lower doses of PCP typically produce feelings of joy (euphoria) and less inhibition, similar to being drunk.
  • Higher doses cause numbness throughout the body, and perception changes that may lead to extreme anxiety and violence.
  • Large doses may produce paranoia, "hearing voices" (auditory hallucinations), and psychosis similar to schizophrenia.
  • Massive doses, usually from taking the drug by mouth, may cause acute kidney failure, heart arrhythmias, muscle rigidity, seizures, and even death.

Because of the pain-killing (analgesic) properties of PCP, users who get seriously injured may not feel any pain.

A number of other club drugs have become popular and available in recent years:

  • Ketamine, a substance related to PCP, is commonly called "Special K."
  • MDMA, or "Ecstasy" (3,4-methylenedioxy-methamphetamine)
  • y-hydroxybutyrate (GHB) and Rohypnol are known as "date rape," "acquaintance rape," or "drug-assisted assault" drugs.


In addition to PCP, other commonly abused hallucinogens include LSD (lysergic acid diethylamide), psilocybin (mushrooms, "shrooms"), and peyote (a cactus plant containing the active ingredient mescaline).

Most hallucinogens are used only one or a few times per year.

Hallucinations related to these drugs tend to involve seeing things, and may include patterns or halos around lights. People who have such visual hallucinations after taking drugs usually know that their perception is distorted.

Signs and symptoms of LSD use:

  • Anxiety
  • Blurred vision
  • Dilated pupils
  • Frightening images of things that aren't there (hallucinations)
  • Paranoid delusions
  • Tremors

LSD is a very strong hallucinogen. Only tiny doses are needed to produce effects. Compared to LSD, psilocybin is 100 - 200 times weaker, and mescaline (peyote) is about 4,000 times weaker.

Hallucinogens can lead to extreme anxiety and lack of reality at the height of the drug experience ("bad trips"). These experiences can come back as a "flashback," even without using the drug again. Such experiences typically occur during times of increased stress, and tend to occur less often and intensely after stopping the drugs.


The abuse of cocaine increased dramatically in the late 1980s and early 1990s, but is now on the decline. Other names to describe different forms of cocaine include "speed," "crack," "coke," "snow," and "speedball."

  • Cocaine may be inhaled through the nose ("snorting").
  • It may be dissolved in water and taken through a vein (intravenously).
  • When mixed with heroin for IV use, the combination is called a "speedball."
  • Through a simple chemical procedure, cocaine may be changed into a smokeable form known as freebase or crack.

Smoking cocaine produces a nearly instant and intense sense of joy (euphoria), which is attractive to abusers. Other effects include:

  • Feelings of increased confidence and energy
  • Less inhibition
  • Local numbness
  • Powerful stimulation of the central nervous system

Increased use of and addiction to cocaine probably occur because it produces a very pleasurable high that is very short lived. This encourages the user to use the drug more often or regularly to get the desired effects.

Both the need to use larger amounts of the drugs to get the same effect (tolerance) and dependence may occur with regular cocaine use. Regular users may have:

  • Depression
  • Loss of interest in school, work, family, and friends
  • Memory loss
  • Mood swings
  • Sleep problems
  • Social withdrawal

Because heavy use may cause paranoia, cocaine users may become violent.


Other names used to describe amphetamines or methamphetamines include "crystal," "go," "crank," and "cross-tops."

During the 1950s and 1960s, amphetamines were often prescribed for conditions such as fatigue, obesity, and mild depression. Such use has stopped because the drugs are very addictive, and are now considered controlled substances.

Over-the-counter (OTC) amphetamine look-alike drugs are often abused. These drugs typically contain caffeine and other stimulants, and are sold as appetite suppressants or stay-awake/stay-alert aids.

Signs and symptoms of stimulant use:

  • Dilated pupils
  • Exaggerated feeling of well-being (euphoria)
  • Fast heart rate
  • Restlessness and hyperactivity
  • Skin flushing
  • Sleep disturbances
  • Tremors
  • Weight loss


Inhalant use became popular with young teens in the 1960s with "glue sniffing." Since then, a greater variety of inhalants have become popular. Inhalant use typically involves younger teens or school-age children. Groups of children will usually use inhalants as an experiment.

Commonly abused inhalants include:

  • Aerosols for deodorants or hair sprays
  • Cleaning fluids
  • Gasoline
  • Liquid typewriter correction fluid
  • Model glue
  • Spray paints

The chemicals are poured into a plastic bag or soaked into rags, then breathed in. The drugs are absorbed through the respiratory tract and cause an altered mental state within 5 - 15 minutes.

Negative effects of inhalant abuse include:

  • Brain damage
  • Convulsions
  • Liver or kidney damage
  • Nerve damage (peripheral neuropathy)
  • Sudden death

Most inhalant use occurs among teens or preteens who do not have ready access to illegal drugs or alcohol.


Opiates come from opium poppies. These drugs include morphine and codeine. Opioids are artificial substances that have the same effect as morphine or codeine. The term "narcotic" refers to either type of drug.

Opiates and narcotics are powerful painkillers that cause drowsiness (sedation) and sometimes, feelings of euphoria.

These drugs include:

  • Codeine
  • Heroin
  • Hydromorphone (Dilaudid)
  • Methadone
  • Meperidine (Demerol)
  • Opium
  • Oxydodone (Percocet or Oxycontin)

Signs and symptoms of narcotic use:

  • Coma, respiratory depression leading to coma, and death in high doses
  • Needle marks on the skin ("tracks") if drug use is by injection
  • Rapid heart rate
  • Relaxed or euphoric state
  • Scars from skin abscesses if drug use is by injection
  • Small "pinpoint" pupils

Because heroin is commonly injected into a vein (used intravenously), there are health concerns about sharing contaminated needles among IV drug users. Complications of sharing contaminated needles include hepatitis, HIV infection, and AIDS.


These substances produce a sedative and anxiety-reducing effect, which can lead to dependence.

These types of drugs include:

  • Alcohol
  • Barbiturates (amobarbital, pentobarbital, secobarbital), also called "yellow jackets"
  • Benzodiazepines (Valium, Ativan, Xanax)
  • Chloral hydrate
  • Paraldehyde

Signs and symptoms of alcohol or other depressant use:

  • Decreased attention span
  • Impaired judgment
  • Lack of coordination
  • Slurred speech


  • If you are concerned about the possibility of getting addicted to any prescribed medications
  • If you are concerned about possible drug abuse by yourself or a family member
  • If you are interested in getting more information on drug abuse
  • If you are seeking treatment of drug abuse for yourself or a family member

Also seek out information and support from local 12-step support groups, such as:

  • Al-anon/Alateen
  • Alcoholics Anonymous (AA)
  • Narcotics Anonymous (NA)

Other support groups include:

  • LifeRing Recovery
  • Moderation Management
  • SMART Recovery

See also:

  • Alcoholism - support group
  • Chemical dependence - support group

Alternative Names

Substance abuse; Illicit drug abuse; Narcotic abuse; Hallucinogen abuse