[00:03.69]1997 Passage3

[00:07.32]Technically, any substance other than food

[00:10.48]that alters our bodily or mental functioning is a drug.

[00:15.31]Many people mistakenly believe the term drug refers only

[00:19.76]to some sort of medicine or an illegal chemical

[00:23.05]taken by drug addicts.

[00:25.47]They don't realize that familiar substances

[00:28.19]such as alcohol and tobacco are also drugs.

[00:32.59]This is why the more neutral term substance is now used

[00:36.61]by many physicians and psychologists.

[00:40.55]The phrase "substance abuse" is often used

[00:43.77]instead of "drug abuse" to make clear

[00:46.39]that substances such as alcohol and tobacco

[00:49.93]can be just as harmfully misused as heroin and cocaine.

[00:55.08]We live in a society in which the medicinal and social

[00:58.60]use of substances (drugs) is pervasive:

[01:02.84]an aspirin to quiet a headache, some wine to be sociable,

[01:07.37]coffee to get going in the morning,

[01:09.89]a cigarette for the nerves.

[01:12.72]When do these socially acceptable and apparently

[01:15.92]constructive uses of a substance become misuses?

[01:20.25]First of all,

[01:21.42]most substances taken in excess

[01:23.85]will produce negative effects such as poisoning

[01:27.17]or intense perceptual distortions.

[01:30.60]Repeated use of a substance

[01:32.42]can also lead to physical addiction or substance dependence.

[01:37.36]Dependence is marked first by an increased tolerance,

[01:41.38]with more and more of the substance

[01:43.30]required to produce the desired effect,

[01:46.83]and then by the appearance of unpleasant withdrawal symptoms

[01:51.18]when the substance is discontinued.

[01:54.37]Drugs (substances) that affect the central nervous system

[01:59.10]and alter perception, mood, and behavior

[02:03.04]are known as psychoactive substances.

[02:06.16]Psychoactive substances are commonly grouped

[02:09.09]according to whether they are stimulants,

[02:11.41]depressants, or hallucinogens.

[02:14.33]Stimulants initially speed up or activate

[02:17.76]the central nervous system,

[02:19.57]whereas depressants slow it down.

[02:23.01]Hallucinogens have their primary effect on perception,

[02:27.36]distorting and altering it in a variety of ways

[02:31.60]including producing hallucinations.

[02:35.32]These are the substances often called psychedelic

[02:39.05](from the Greek word meaning "mind-manifesting")

[02:43.80]because they seemed to radically alter

[02:46.33]one's state of consciousness.