Skip to main content

Understanding where addiction starts and ends.


A drug is defined as any substance that can alter the homeostasis of the body. Individuals consuming these substances can be described as using, misusing, or abusing drugs or any other substances.

Definitions of Drug Use, Misuse, and Abuse:

Drug Use-Drug use is using any substance for its intended purpose. Drug use would include taking an antibiotic or sleeping pill as prescribed, using an occasional antacid, drinking wine with dinner, or a cup of coffee at breakfast.

Drug Misuse-Drug misuse is use of a drug that may result in transient physical, mental, or social problems. Drinking alcoholic beverages or smoking marijuana for improved social skills would be drug misuse. Giving a prescription to a friend or family member because he or she has the same symptoms as you do, or taking more of a medication and at more frequent intervals than prescribed, would also be considered drug misuse.

Drug Abuse-Drug abuse is use of a substance that results in long-term physical, mental, or social problems. Using heroin or barbiturates to get high repeatedly, becoming dependent upon alcohol, or smoking marijuana continuously to escape the realities and responsibilities of life would be examples of drug abuse. Using a laxative every day would also be considered to be drug abuse.


Harm to the Individual and Society


Drugs can be classified or ranked ordered according to their hazard potential to the individual and/or society.

Harm to the individual would include:

– significant organ or tissue damage, potential for tolerance, physiological or psychological addiction, harm to an unborn child, increased death rate from use or abuse of the substance.

Harm to the society would include:

– increased rates of death of others (i.e. drunk driving), increased insurance rates, loss of working days, crimes of violence, disability payments, family breakdown, and mental, physical, or sexual abuse from the use or abuse of the substance.

Current research has led to the formulation of the following rank ordering of drugs, in terms of degree of harm to the individual and to society:

  1. Alcohol
  2. Tobacco
  3. Sedative-hypnotics
  4. Cocaine
  5. Heroin
  6. Tranquilizers
  7. Narcotic-analgesics other than heroin
  8. Amphetamines
  9. PCP
  10. Volatile Substances
  11. Hallucinogens
  12. Marijuana (Cannabis sativa)
  13. Antihistamines
  14. Xanthines

It should be noted that this rank ordering of drugs, is, of course, open to debate, as there are many opinions as to what might or might not be harmful to the individual and to the society. As an example, is it worse for a pregnant woman to drink heavily during pregnancy, producing a mentally and physically handicapped baby, or for someone to rob and maim a person to obtain money for heroin, or for a bright student to neglect family, friends, studies, and possible future by heavily using and selling marijuana and hallucinogens? The potential debate in the rank ordering and classification of drugs by their harmful effect or legality suggests that all classifications and rank ordering are open to criticism and are dependent upon varied opinions, values, and ways of looking at drugs and their use in a society. It also suggests that even though some substances may be legal for consumption in our culture, they may cause serious harm to the individual and to society. Therefore, after studying information in this text and other references concerning drugs, you may wish to determine your own rank ordering of the danger of various drugs to the individual and/or to society.


Terminology of Drug Action



Tolerance to a drug develops when the response to the same dose of the drug decreases with repeated use. As an example, if you are an occasional drinker, you may become intoxicated after drinking three beers. However, after drinking every night for a week, you may find that it takes five beers to get that same feeling. This would indicate a developing tolerance to alcohol. The rate at which an individual develops tolerance to a drug depends upon that individual’s heredity, the dose of the drug, the size of the person, and the frequency of drug administration. Tolerance usually occurs with depressants, which include alcohol, opiates, synthetic narcotics, barbiturates, some minor tranquilizers, and volatile substances such as ether and glue. Tolerance to amphetamines, when used in large doses, has also been found.


Withdrawal Symptoms

When one has become physically dependent upon a drug and abruptly abstains from the substance, a psychological and/or physiological reaction occurs. The reaction is the opposite of the effect of the drug. In withdrawal from a depressant drug, restlessness, irritability, nausea, tremors, inability to sleep, and sometimes, in the case of alcohol and barbiturates, convulsions that may lead to death may occur.


Addiction (Physical Dependence)

Addiction has often been considered to be physical dependence upon a drug. This generally occurs with depressant drugs, which include alcohol, barbiturates, tranquilizers, and opiates. Increased tolerance to the substance and withdrawal symptoms upon cessation of use are usually present. However, according to L.J. Hatterer, “we now extend addiction to relate to almost any substance, activity or interaction, as well as to drugs”. The individual has an overpowering need for the substance, object, or activity that produces a psychological and/or physiological high. The desire or need is repetitive, impulsive, and compulsive in nature. If the person ceases the activity or abstains from the substance, withdrawal symptoms usually occur.


Habituation (Psychological Dependence)

Habituation was at one point considered to be psychological dependency upon a substance or activity. However, with the expanded definition of addiction to include the addictive behaviors or the addictive process, which can apply to any activity, interaction or object, this term is not used as frequently as it was in the past. Psychological withdrawal symptoms, including irritability, depression, and sleep disturbances often accompany habituation.

Adapted from Engs, R.C. Alcohol and Other Drugs: Self Responsibility, Tichenor Publishing Company, Bloomington, IN, 1987. (c) Copyright Ruth C. Engs, Bloomington, IN, 1996. Retrieved 11 August 2008 from