From O’Shaughnessy’s report on the International Cannabinoid Research Society’s 2002 meeting:
William Notcutt recounted that he and colleagues at the James Paget Hospital in Great Yarmouth used Sativex —GW Pharmaceuticals’ extract formulated for spraying under the tongue— in clinical trials involving 29 chronic pain patients. Initially patients were given a 1:1 mix of THC and CBD for two weeks. The 27 who reported benefits than received, over the next eight weeks, one-week treatments with high-THC, high-CBD, placebo, and 1:1 THC/CBD extracts.
The order in which patients used the various extracts was unknown to either them or the doctors. This method, in which each patient is his/her own control, is called an “N=1” trial.
Patients were assessed weekly. Notcutt reported that 24 of the 27 patients showed consistent benefit: “Improvements in pain, sleep, depression, activity and general health were the most important… All of the 24 patients who showed benefit have started a long-term safety extension of the study.”