The cost were obtained from the literature (CIPFA 1992, Hatziandreu et al, 1994, Drug Tariff 1995) and were inflated to 1994. These studies measured the treatment cost, which included drug cost and GP visits cost; the cost of treatment failure which included the drug cost, GP visits, hospitalisation, psychotherapy and ECT. The cost of treatment failure was based on estimates from the physicians' panel. All costs were expressed in 1994 values. Costs and quantities were measured separately.