In considering whether to attempt to develop an immunotherapy or depot medication, the relevant comparison is between, on the one hand, the aggregate amount by which the benefits of use would exceed the costs, summing over total applications and, on the other hand, the development costs, appropriately adjusted both for the risks of failure—failure to develop a safe and efficacious medication, failure to secure regulatory approval, failure of adoption by providers and patients—and for the time value of money (Hubbard and French, 1991).
In addition to the benefits that accrue to patients who use the new therapy in place of other treatments, there would be another, potentially much larger, flow of benefits from patients attracted to try desistance from heavy use by the availability of a treatment that might be less effortful as well as more likely to succeed.
Against those benefits must be set the costs, including the opportunity cost of the treatment dollars that would pay for administration of a new therapy. But that sort of opportunity-cost analysis implicitly assumes that the overall level of funding is invariant to the range of therapies available, and that assumption may not be valid in this case. There are reasons to expect that an effective immunotherapy or depot medication might turn out to have characteristics more appealing to those who make decisions about drug treatment than its current competitors. The most demonstrably effective drug treatments in use today are the opiate substitution therapies, which are highly acceptable to many, though far from all, persons suffering from opiate dependency but which remain controversial politically because they do not promise a “cure” for the underlying addiction. Other treatments, while no one doubts their utility for some patients, face lower success rates and more resistance among potential clients, as reflected in both reluctance to enter treatment and high rates of dropout and treatment recidivism. These facts constitute part of the political background against which funding decisions are made and also of the professional background against which medical providers make treatment decisions, insurers make coverage decisions, and medical schools and other educators of health care professionals design curricula. It is not at all far-fetched to imagine the development of effective immunotherapies as a catalyst for changes in attitudes that would lead to changes in funding.
The sheer magnitude of the social costs of substance abuse means that even development programs with modest probabilities of success will be cost-justified. A treatment for smoking that had net benefits per patient measured in thousands of dollars, and a potential patient base measured in tens of millions, would have development benefits that might rise into the tens of billions. The potential patient base for treatment of cocaine addiction is more than an order of magnitude smaller, but the potential gains per patient are in the range of an order of magnitude greater, sug-