There has been little research into the efficacy of combining TCM with mainstream medicine. The medical profession seems generally resistant to this avenue of approach and appears to be reluctant to conduct clinical trials. This may be partly due to the cost and the fact that herbalists are not in a financial position to underwrite such trials in the same way that drug companies do for medicines. However there are some encouraging signs: doctors at two central London hospitals are now trying to set up trials into standardised adjunct Chinese Herbal Therapy for patients taking interferon and interferon plus ribavirin (Dolan M, 1998). TCM can also be used to treat many other residual health problems associated with long term substance misuse as well as providing herbal remedies for detox, and cessation of cravings.