Patients who use drugs intravenously may be at high risk for relapse, but their situation is no more futile than that of persons with diabetes and coronary artery disease who smoke and frequent all-you-can-eat buffets.
Specific contributions to a scientific article entitle the contributor to be included as an author; requests for authorship by those who have not made those specific contributions are unethical.
The bias for publishing positive clinical-research results can cause physicians to question journal articles as dependable sources of product information.