Loss of memory, lack of motivation, and diminished attention span are some of the effects of regular marijuana use. Long-term use may result in psychological dependence and change in tolerance. The use of depressants can result in a change in tolerance and in physical, as well as psychological dependency. Withdrawal symptoms include anxiety, vomiting, acute psychotic episodes, seizures, and death. High doses of stimulant drugs result in intense personality disturbances including visual and auditory hallucinations, delusions, and paranoia.
Tolerance develops rapidly.
The use of cocaine can cause death by cardiac arrest or respiratory failure. Stimulants are addictive and while withdrawal from stimulants is less dangerous than with depressants, depression can make the person vulnerable to suicide. Tolerance, especially to the euphoric effects of narcotics, and physical dependence develop rapidly. In order to avoid the abstinence syndrome, the addict becomes preoccupied with acquiring the drug. Large doses of PCP may result in convulsive seizure, coma, and death.