Shrader-Frechette, 1991).¹ But the literature on technological risks also documents the dangers posed by excessive optimism on the part of enthusiastic program designers (e.g., Janis, 1983; MacCoun, 1998a; Tenner, 1996; Vaughan, 1996). Thus, in the spirit of “devil’s advocacy,” it has been chosen in this appendix to err on the side of caution, giving greater attention to arguments in support of various unintended consequences than to possible counterarguments (which are nevertheless noted).

The committee has identified three types of immunotherapy or depot medication treatment protocols: overdose treatment, relapse prevention, and protection from addiction. Overdose treatment appears to be less susceptible than the other two categories to unintended consequences created by behavioral responses to the intervention, at least with respect to the mechanisms considered here. And to the extent that overdose treatment might operate via those mechanisms, its effects are likely to be similar to those of a relapse prevention program, only weaker. Thus, this appendix focuses primarily on relapse prevention and secondarily on the somewhat more remote prospect of addiction protection.

For simplicity the focus here is on interventions that target tobacco and cocaine use. Tobacco illustrates issues involved in pharmacological treatments for a legal, commercially available drug, and cocaine exemplifies issues posed for an illicit recreational drug.

Psychoactive drug use is a multidimensional behavior characterized by many continuous parameters: age of onset, length of drug-use career, variety of drugs used, frequency of use, quantity consumed per use, and so on. To simplify the discussion, all this detail is abstracted away and drug use is characterized in terms of four mutually exclusive states. Figure H-1 presents a stochastic flow diagram, modified from a similar diagram used by Everingham and Rydell (1994). The figure depicts drug-using careers as patterns of movement among four “states”: never used, light use, heavy use, and former use. Among users, program participants are distinguished from nonparticipants and use of the target drug versus