Marijuana adversely affects the short-term memory. When marijuana is smoked, THC and other chemicals in plants pass from the lungs into the bloodstream, which rapidly carries them throughout the body to the brain. Effects may be experienced almost immediately, many people experience a pleasant euphoria and sense of relaxation. People who have taken large doses of marijuana may experience an acute psychosis, which includes hallucinations,delusions, and a loss of the sense of personal identity.