Heroin addiction is a chronic, relapsing and remitting condition. Each year 2–5% of addicts discontinue drug use permanently and 1–2% die, mostly of overdose (Robins, 1993). A study of 129 opiate-addicted patients on a monthly maintenance regimen found that those with a family history of opium use had an earlier age at onset (Chaudhry et al, 1991). Long-term follow-up studies of people who misuse opiates have revealed that opioid dependence appears to run a chronic, relapsing and remitting course with a significant mortality (10–15%) over 10 years (Robson, 1992). Metrebian et al (1998) reported that long-term heroin abstinence was associated with less criminality, psychological distress and morbidity; Hser et al (2001) reported it was associated with higher employment rates.