depressants depress sympathetic NS, decrease brain activity, decrease glucose metabolism:
1. alcohol- stimulate GAPA and dopamine, suppress REM
2. *barbiturates*- sedatives, sleep aids, depress sympathetic NS
3. *opiates*- mimic endorphins to relieve pain, examples are morphine and heroin
4. *benzodiazepines*- stimulate GABA, anti-anxiety
stimulants activate sympathetic NS, increase brain activity, increase glucose metabolism:
1. release neurotransmitter or prevent reuptake
2. caffeine, nicotine- cause a rush
3. cocaine- release dopamine, serotonin, norepinephrine
4. ecstasy- release dopamine and serotonin
5. amphetamines- meth
hallucinogens make you see things, can be either stimulating or depressing, no dependence:
1. marijuana- THC stimulates cannabinoid receptors, amplifies sensory perception
2. LSD- emotional, out-of-body