Addiction to a psychoactive substance such as alcohol or heroin is a complex biopsychosocial problem. Once an individual is dependent on a substance and seeking professional treatment, the natural history of the problem is likely to involve many years of struggle, with periods of abstinence quickly followed by lapse and relapse back to regular use (Hser, Longshore, & Anglin, 2007). Many people do reach the status of sustained abstinence and recovery, but mortality rates are high and the problem is often accompanied by high levels of morbidity in the individual and their family (Darke, 2011).