Nicotine addiction is the primary source of physiological dependence in relation to tobacco smoking and serves to play a major role in continued tobacco use because of its physiological effects on the body. Nicotine is a stimulant drug with the ability to cause both stimulation and relaxation. In smaller doses smoking heightens feelings of excitement and thus relieves fatigue and depression. In larger doses nicotine exerts a calming effect and reduces tension and stress however, the mental and physical state of the smoker can influence the person's perceptions of the effect of smoking hence the overall experience will be different for different people (CDC, 1988). What seems to be certain is that nicotine is very addictive with tobacco being its method of administration (Physicians, 2000) and is characterised by a compulsive drug seeking behaviour even in the face of negative health consequences. Further buttressing its addictive nature, nicotine has been compared to other drugs of addiction such as heroin and cocaine in relation to their action as a mood/behaviour altering agent. Nicotine's pharmacokinetics also enhance its potential as a drug of abuse as tobacco smoking causes a rapid distribution of nicotine into the effect achieving its desired effect of pleasure. The effect is short lived because of the short half life of the drug in the system, leading the smoker to want more and more of the drug so as to sustain its pleasurable effects, and this accounts for the tolerance and dependence bit of physiological dependence. Perhaps the hardest part of quitting is dealing with the withdrawal symptoms. High relapse rates have been largely attributed to the inability to deal with withdrawal symptoms. These symptoms include irritability, craving, depression, anxiety, cognitive and attention deficit, sleep disturbances, and increased appetite and may begin within a few hours after the last cigarette, quickly driving people back to the habit. Symptoms peak within the first few days of smoking cessation and usually subside within a few -weeks. For some people, however, symptoms may persist for months. Although withdrawal is related to the pharmacological effects of nicotine, many behavioural factors can also affect the severity of withdrawal symptoms. For some people, the feel, smell, and sight of a cigarette and the ritual of obtaining, handling, lighting, and smoking the cigarette are all associated with the pleasurable effects of smoking and can make withdrawal or craving worse.