PSYC62H3 Chapter 6: chapter6
Document Summary
Drug tolerance occurs when there is decreased susceptibility (diminished response) to the effects of a given amount of drug as a result of previous exposure, typically caused by repeated exposure to the drug. Increasingly larger doses of drug are required to induce the same behavioural effect. Tolerance due to drug exposure id different from so-called genetic or dispositional tolerance, whereby an individual may not be effected by the drug as much as other individuals are because of genetic or dispositional factors. In this form of tolerance, the same amount of drug administered on two separate occasions a couple of hours apart may induce greater effects with the first dose than with the second doses. Tachyphylaxis is also evident when the behavioural or physiological effects of a given dose of drug dissipate at a faster rate than the rate at which the drug is eliminated from the brain.
