Wired ran an article entitled "Chemical Concussions and Secret LSD: Pentagon Details Cold War Mind-Control Tests" about a government memo that was recently released. The document is, "Experimentation Programs conducted by the Department of Defense That Had CIA Sponsorship or Participation and That Involved the Administration to Human Subjects of Drugs Intended for Mind-Control or Behavior-Modification Purposes," and it contains a gem (on page 8, paragraph 2): noted as part of a program to identify a "nonaddictive substitute for codeine," funded by the Navy:
It appears that the researcher tested some 800 compounds on addicted patients...Three compounds were retained and all are now common drugs [including] dextromethorphan which is used in cough syrup.