Comer and colleagues1 have shown that an injectable, sustained-release formulation of naltrexone can be effective for the treatment of opioid dependence in selected individuals. While these findings are promising, the impact of this treatment option will likely be limited by low rates of patient acceptance.2 Unfortunately, the authors have given us a long list of exclusion criteria but do not provide any data on the number of heroin-dependent men and women who were screened to recruit the 60 subjects in their study. Furthermore, it appears that they used a run-in period during which all subjects received naltrexone to see whether “they were willing and able to tolerate the effects of depot naltrexone”; it would be very helpful if the authors reported how many subjects dropped out during this phase of the trial. I am surprised that the Archives did not adhere to the CONSORT guidelines3 (which it endorses) in requiring the authors to provide a flow diagram showing the number of subjects assessed for eligibility and the numbers excluded.