Cocaine use triggers the release of dopamine, a chemical that transmits feelings of pleasure and well-being, in the brain. The brain requires more and more dopamine to be released to satisfy its needs, which in turn requires greater amounts of cocaine to be used. An individual becomes more tolerant of the effects and has to use greater amounts to achieve the same high. Repeated compulsive use of cocaine may lead to highs that produce no pleasurable feelings. Affected users become anxious, believe they have superhuman powers, or become suspicious and paranoid, to the point that they believe the are in danger and react in bizarre or violent ways.
Hallucinations are also common.
A cocaine high is often followed by a crash lasting 30 to 60 minutes or longer and leaving the user feeling tired and irritable. Cocaine use provides relief from these symptoms, creating the cycle of use. Generally, the higher a person gets on cocaine, the worse the effects of the crash. Whether or not an individual experiences a crash depends on the individual and the amount of cocaine used. Withdrawal following prolonged use of cocaine can cause irritability, nausea, agitation, sleep disorders, severe depression, muscle aches and an intense craving for the drug.