A method for estimating a risk of relapse of addictive behavior related to exposure to an addictive stimulus, the method including the steps of, at multiple points in time, requesting the individual to measure exposure to the stimulus or answering a questionnaire, measuring the individual's exposure to the stimulus and collecting the individual's questionnaire answers, transmitting a result from the measurement device to a central server unit, storing the result in the central server unit, estimating a risk of relapse based on a combination of the received result and historic results, determining a next point in time for requesting the individual to do at least one of conducting a measurement of the individual's exposure to the stimulus and answering a questionnaire, based on the estimated risk, and if the estimated risk is greater than a predefined level, transmitting a message to a third party informing about the estimated risk.