Expert: What criteria distinguish addictive substances from nonaddictive ones  Some have suggested that any substance that at least some habitual users can cease to use is nonaddictive  However, if this is taken to be the sole criterion of nonaddictiveness, some substances that most medical experts classify as prime examples of addictive substances would be properly deemed nonaddictive
Any adequate set of criteria for determining a substance' s addictiveness must embody the view, held by these medical experts, that a substance is addictive only if withdrawal from its habitual use causes most users extreme psychological and physiological difficulty
Fewer substances would be deemed addictive than are deemed so at present if an adequate definition of addictive were employed.