| Drug | Classification | Effects | Potential Harm |
| Alcohol | Depressant | disinhibition, feeling “high” | coma, death |
| Barbiturates | Depressant | decreased neural activity, relaxation, possible aggression | loss of consciousness, coma, death |
| Caffeine | Stimulant | alertness, enhanced recall, elevated mood, endurance | heart races, trembling, insomnia |
| Cocaine | Stimulant | energy, euphoria, rush of pleasure | heart attack, stroke, anxiety, psychosis |
| Heroin | Depressant | pleasure-inducing, reduces pain, rush of euphoria and relaxation | boils on the skin, hepatitis, liver disease, spontaneous abortion |
| LSD | Hallucinogen | extreme changes in sensation and perception, emotional rollercoaster | depression, long-term flashbacks, other psychological problems |
| Marijuana | Hallucinogen | stimulates appetite, suppresses nausea, relaxation, mild euphoria, distortion of time, intense sensory experience | respiratory problems, immune system suppression, cancer, memory impairment, deficits in attention and learning |
| MDMA | Stimulant; hallucinogen | euphoria, heightened energy, anxiety, and depersonalization | blurred vision, dizziness, rapid heart rate, dehydration, heat stroke, seizures, cardiac arrest, and death |
| Methamphetamine | Stimulant | energy, alertness, increases sex drive, suppresses appetite | lasting memory and movement problems, severe weight loss, tooth decay, psychosis, sudden death |
| Opioids | Depressant | blocks pain, induces drowsiness, euphoria, slows down breathing | respiratory problems during sleep, falls, constipation, sexual problems, overdose |
| Tobacco | Stimulant | relaxed, alert, more tolerant of pain | cancer, emphysema, heart disease, stroke, reduction in life span |
| Most drugs can be classified under one of the major categories listed above, but there are substances, such as MDMA, that fall into more than one class. Psychoactive drugs carry serious risks. |