Reverse tolerance

Reverse tolerance is the phenomenon of a reversal of the side-effects from a drug, or the reduction of insensitivity caused after drug tolerance has been established. Typically this involves the use of an additional medication, or abstinence from a drug for a period of time, known as a drug holiday. Such drugs include amphetamines, or SSRIs. As a result, regular users commonly experience a quick decrease of unwanted side effects, without an equivalent loss of its stimulant properties. Notably, the sensitization is induced more quickly, and persists far longer than withdrawal-related effects, suggesting a phenomenon more complex than a simple tolerance-induced withdrawal syndrome.