Once a Smoker, Always a Smoker?

There are over 23.5 million Americans that are addicts. Common addictions are cocaine, marijuana, painkillers, and alcohol. However, more individuals in the United States of America are addicted to nicotine than anything else.  With over 40 million nicotine addicts in the U.S., nicotine addiction has become a major issue, especially due to the correlated health effects from chronic use of nicotine. Heavy users of nicotine are more likely to develop heart disease, stroke, and lung cancer.

Daniel McGhee spoke at Loyola University Chicago about the research his fellow colleagues and him conducted which provided additional evidence of the effect of nicotine. Dr. McGhee mentioned that activation of nicotinic receptors via nicotine, cause the brain activity to activate which can be both rewarding and addicting for the brain. In fact, after exposing “nicotine to brain slices from drug-Naïve adults rats” with a recovery period, “ it was noted that there was “NMDA receptor (NMDAR)-dependent increase of AMP receptor/NMDAR ratio in VTA DA neurons, which is consistent with the induction of LTP.” In other words, the experiment conducted by Dr. McGhee and his colleagues, noted that even after a miniscule amount of exposure to nicotine, AMPA/NMDA ratios within the VTA increase.  In fact, Dr. McGhee mentioned that plasticity of the brain begins to occur after 2-4 of nicotine exposure. Thus, if an individual is chronically using nicotine, ratios of AMPA/NMDA will increase which will cause the brain to become addicted to nicotine.

Once the brain becomes addicted to nicotine, it becomes hard for an individual to quit using nicotine. In the journal of Diabetes Care, Dr. David Mannino, mentions that activation of nicotinic receptors leads to positive effects such as “pleasure, arousal, and the reduction of anxiety and tension”. However, habitual use of nicotine will also result in “both a desensitization of these receptors to nicotine and an increase in the number of receptors”.  Yet, when and individual tries to quite “desensitized receptors may recover and elicit symptoms of withdrawal” such as “irritability, depressed mood, anxiety, difficulty concentrating, insomnia, and caving”. Thus, these changes prompt an individual to use nicotine again. In fact, in a recent study it was calculated that there is an 80% relapse rate within the first month of quitting nicotine.

References:

Dr. Daniel McGhee’s Presentation on February 23, 2013 at Loyola University Chicago

Article 1: http://care.diabetesjournals.org/content/32/suppl_2/S426.full

Picture 1: https://static-secure.guim.co.uk/sys-images/Guardian/Pix/pictures/2012/11/30/1354283386179/smoking-addiction-008.jpg

Picture2: http://static1.squarespace.com/static/54db756ae4b0cf15c28e7b8a/t/54e21e30e4b0bb15dcacc4c9/1424105009889/tumblr_mlsetsKySj1rkz363o4_1280.jpg