Drug Dependence.

« these drugs develops rapidly, no withdrawal syndrome is apparent when they are discontinued. Phencyclidine, or PCP, known popularly by such names as “angel dust” and “rocket fuel,” has no medical purpose for humans but is occasionally used by veterinarians asan anesthetic and sedative for animals.

It became a common drug of abuse in the late 1970s, and is considered a menace because it can easily be synthesized.

Itseffects differ from those of other hallucinogens.

LSD, for example, produces detachment and euphoria, intensifies vision, and often leads to a crossing of senses (colorsare heard, sounds are seen).

PCP, by contrast, produces a sense of detachment and a reduction in sensitivity to pain, and may trigger or produce symptoms so likethose of acute schizophrenia that professionals confuse the two states.

The combination of this effect and indifference to pain has sometimes resulted in bizarrethinking, occasionally marked by violently destructive behavior. VI CANNABIS The plant Cannabis sativa is the source of both marijuana and hashish.

The flowering tops of the Cannabis plant secrete a sticky resin that contains the active ingredient of marijuana and hashish.

Hashish is comprised of only the flowering tops of the plant, whereas marijuana is made up of flowering tops and leaves.

Both drugs areusually smoked.

Their effects are similar: a state of relaxation, accelerated heart rate, perceived slowing of time, and a sense of heightened hearing, taste, touch, andsmell.

These effects can differ, however, depending on the amount of drug consumed and the circumstances under which it is taken.

Marijuana and hashish do notproduce psychological dependence except when taken in large daily doses.

The drugs can be dangerous, however, especially when smoked before driving.

Although thechronic effects have not been clearly determined, marijuana is probably injurious to the lungs in much the same way as tobacco.

A cause for concern is the regular useby children and teenagers, because intoxication markedly alters thinking and interferes with learning.

A consensus exists among physicians and others who work withchildren and adolescents that use of marijuana and hashish is undesirable and may interfere with psychological and possibly physical maturation. Cannabis has been used as a folk remedy for centuries.

Its active ingredient, delta-9-tetrahydrocannabinol (THC), has been used experimentally for treating alcoholism,seizures, pain, the nausea produced by anticancer medications, and glaucoma.

Glaucoma patients have used THC successfully, but the disorienting effects limit itsusefulness for cancer patients. VII INHALANTS This class includes substances that are usually not considered drugs, such as glue, gasoline, and aerosols like nasal sprays.

Most such substances sniffed for theirpsychological effects depress the central nervous system.

Low doses can produce slight stimulation, but higher amounts cause users to lose control or lapse intounconsciousness.

The effects, which are immediate, can last as long as 45 minutes.

Headache, nausea, and drowsiness follow.

Sniffing inhalants can impair vision,judgment, and muscle and reflex control.

Permanent damage can result from prolonged use, and death can result from sniffing highly concentrated aerosol sprays.Although physical dependence does not seem to occur, tolerance to some inhalants develops.

Another source of medical concern is the widespread misuse, for asupposed aphrodisiac effect, of so-called “poppers”—chemicals such as isoamyl nitrite that have legitimate medical functions as blood vessel dilators (vasodilators).Continued sniffing of these easily obtainable substances can damage the circulatory system and have related harmful effects. VIII TREATMENT With the exception of treatment of opioid dependence, medical attention to the problems of the drug abuser is largely confined to dealing with overdoses, acutereactions to drug ingestion, and the incidental medical consequences of drug use such as malnutrition and medical problems caused by unsterilized needles.

Abusers ofbarbiturates and amphetamines may require hospitalization for detoxification, as is common among alcoholics.

Others, such as those arrested repeatedly for possessionof marijuana, may, in lieu of imprisonment, be forced to undergo treatment designed primarily for opioid abusers.

Whatever the substance abused, the goal of mosttreatment programs is to foster abstinence in the patient. Two types of treatment programs are used for most opioid users.

Therapeutic communities require the drug abuser to take personal responsibility for his or herproblem.

Typically, the idea behind this treatment is that the drug abuser is emotionally immature and must be given a second chance to grow up.

Harsh encounterswith other members of the community are typical; the support of others, together with status and privilege, are used as rewards for good behavior. The other model for opioid abuse treatment is the use of heroin substitutes.

One such substitute is methadone, which acts more slowly than heroin but is still addictive.The idea is to help the user gradually withdraw from heroin use while removing the need for finding the drug on the street.

A more recent treatment drug, naltrexone,is nonaddictive but does not provide an equivalent “high;” it also cannot be used by persons with liver problems, which are common among addicts. IX SOCIAL ISSUES Drug use for nonmedical purposes occurs throughout society.

For this reason the 1978 President’s Commission on Mental Health did not recommend health and mental-health assistance except to persons whose drug use was intense and compulsive.

The commission identified heroin as the number one drug problem because heroinaddiction may lead to criminal behavior to pay for the drug.

Adding to the problem is the fact that chemically similar drugs can be synthesized and sold on the streetbecause they are not yet classified as controlled substances. In a 1999 household survey by the Substance Abuse and Mental Health Services Administration an estimated 14.8 million people in the United States classifiedthemselves as current illicit drug users.

Among youths aged 12 to 17, close to 8 percent of respondents were regular users of marijuana.

The percentage of youths inthe same age range who used cocaine at least once a month was 49.8 percent.

The survey also reported an estimated 1.6 million U.S.

residents used prescription drugsfor nonmedical purposes in 1998.

The state with the highest rates of dependence on illicit drugs was Alaska with 2.8 percent of its 12 and older population dependenton illicit drugs and 7.3 percent dependent on illicit drugs or alcohol. Contributed By:Robert C.

PetersenMicrosoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation.

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