It is based on the stages of change model developed by Prochaska and DiClementel which describes the stages through which a person moves in an attempt to resolve an addictive problem. From “Precontemplation” through “Contemplation” and “Action” to “Maintenance”, the person is assumed to pass from one stage to the next, with the Relapser re-entering the cycle at either the Precontemplation or Contemplation stages. It may take many cycles around the stages of change before an addictive problem is finally solved.