The effects of stimulants vary from 5 minutes to several hours, depending on which type of CNS Stimulant is used. Overdose of CNS Stimulants can replace the euphoric effect with feelings of panic. The user may become very confused, and suddenly aggressive. They can suffer convulsions, and possibly faint or pass into a coma. This may lead to cardiac arrest.
Death can also occur from sudden respiratory failure.
Another danger is that subjects or their friends may try to counteract a stimulant overdose with barbiturates, possibly leading to an overdose of CNS Depressants.