Barbiturate withdrawal symptoms can include anxiety, irritability, elevated heart and respiration rate, muscle pain, nausea, tremors, hallucinations, confusion, and seizures.
Opiates such as heroin convert to morphine in the body which then activates opiate receptors located throughout the brain and central nervous system, including within the reward system.
Inhalants are breathable chemical vapors are intentionally inhaled because of the chemicals' mind-altering effects.
The most common form of dry magic mushrooms used in the United States is psilocybin cubensis.