Smokers who quit merely become irritable for a few days. While some usenicotine patches, with mixed results, most smokers who quit successfullysimply quit. 4,4 Withdrawal refers to the severity of symptoms experienced uponcessation. Reinforcement refers to the tendency to self-administer, and has beenobserved in laboratory rats. Tolerance refers to an increase in the amount of a drug necessary toexperience the same effect.
Intoxication refers to the degree to which functionality is impaired.
Dependence is not so rigorously defined. It appears to refer to thedetermination of the subject to continue using the substance in question,or perhaps simply to the pleasure experienced. Prior totheir report, addictiveness had been assessed based solely upon the othercriteria. While the other four can be quantified to some extent, thedependency rankings were subjective, based upon the doctors' personalopinions and experience. The list they produced has nicotine at the topbecause it was sorted on the dependency column.