Nicotine gum and spray give an almost immediate hit of nicotine. Patches on the other hand release a gradually sustaining amount of nicotine throughout the day, and therefore do not provide as much positive reinforcement.
NRTs appear to desensitise the brain's nicotine receptors, which makes smoking whilst on one of the drugs a lot less satisfying.
NRT has proven to be very effective in relieving withdrawal symptoms from tobacco, even in small doses. However, it only seems to treat the biological side of the addiction, and does not target the associations smokers have with certain times of the day and places with smoking.
Smokers are also very prone to relapse whilst on NRT, as it delivers nicotine to the bloodstream at a much slower rate than a cigarette does. On the other hand, it is a much healthier alternative to smoking, and is considered less harmful.
Nonetheless, nicotine still has its limitations on health; it increases heart rate and blood pressure, and can aggravate diabetes. Additionally, although it is not a direct cancer causing chemical, animal research has suggested that it promotes tumour growth.
Bupropion is an antidepressant which increases the levels of dopamine and noradrenalin in the brain. This stimulates the effect of nicotine on the neurotransmitters, which is thought to block the nicotine receptors in the brain.
Effectively this makes the person taking the drug less likely to experience positive effects from smoking.
Psychologists such as Watts have found this to be a very successful method in treating smoking addicts.
Champix is another antidepressant, which works exactly the same way as Bupropion by increasing the levels of dopamine and thus reducing nicotine levels in the brain.
Clinical trials have found this to be even better than Bupropion in helping people stop smoking. It has also shown to reduce the likelihood of relapse in smokers who had been abstinent after 2 weeks of therapy.
Overall, all biological interventions have shown to be more effective than a placebo in clinical trials. However, these types of medical treatments usually only treat withdrawal symptoms rather than the cause of the addiction.
Furthermore, they assume that addiction is a disease, which grants a more humane understanding on addiction, as it takes away individual blame.
On the contrary this also takes away the individual's free will, suggesting that they have no control over their addiction. A person may be fully capable of changing their addictive habits by themselves, but biological interventions rely on the deterministic assumption that this is not possible.