Time to Relapse Questionnaire (TRQ): a measure of sudden relapse in substance dependence.

Background: Relapse may occur suddenly, following a short period of craving, or after extended consideration. The time to relapse may reveal underlying mechanisms of relapse and have important implications for treatment.

Objective: The Time to Relapse Questionnaire (TRQ), a self-administered questionnaire, was designed to assess the time from the initial thought of drug use to actual use.