Alcohol Type: Depressant

Pleasurable Effects: initial high followed by relaxation and disinhibition; Possible Negative Effects: depression, memory loss, organ damage, impaired reactions

Heroin Type: Depressant

Pleasurable Effects: rush of euphoria, relief from pain; Possible Negative Effects: depressed physiology, loss of natural endorphin function

Caffeine Type: Stimulant

Pleasurable Effects: increased alertness and wakefulness; Possible Negative Effects: anxiety, restlessness, insomnia in high doses

Nicotine Type: Stimulant

Pleasurable Effects: arousal and relaxation, sense of well-being; Possible Negative Effects: heart disease, cancer

Cocaine Type: Stimulant

Pleasurable Effects: rush of euphoria, confidence, energy; Possible Negative Effects: cardiovascular stress, suspiciousness, depression, crash

Methamphetamine Type: Stimulant

Pleasurable Effects: euphoria, alertness, energy; Possible Negative Effects: irritability, insomnia, hypertension, seizures

Ecstasy (MDMA) Type: Stimulant

mild hallucinogen; Pleasurable Effects: emotional elevation, disinhibition; Possible Negative Effects: dehydration, overheating, depressed mood, impaired cognitive and immune functioning

LSD Type: Hallucinogen

Pleasurable Effects: visual "trip"; Possible Negative Effects: risk of panic

Marijuana (THC) Type: Mild hallucinogen

Pleasurable Effects: enhanced sensation, relief of pain, distortion of time, relaxation; Possible Negative Effects: impaired learning and memory, increased risk of psychological disorders