In the DSM-IV-TR, substance-related disorders are divided into depressants (alcohol, barbiturates, and benzodiazepines), stimulants (amphetamine, cocaine, nicotine, and caffeine), opiates (heroin, codeine, and morphine), and hallucinogens (marijuana and LSD). Specific diagnoses are further categorized as substance dependence, substance abuse, substance intoxication, and substance withdrawal.
Provide a brief definition of addiction, in your own words. What are the similarities and differences in the levels of involvement in the following substance-related stages of addiction: use, intoxication, abuse, and dependence? Discuss why people continue to use substances, despite negative consequences.