Wednesday, July 30, 2014

Motivation and the Brain: Quitting Smoking




Dr. C. Everett Koop, former Surgeon General of the United States once stated that “cigarette smoking is clearly identified as the chief, preventable cause of death in our society” (Reinhold, 1982, para 2).  The addictive properties of nicotine can be felt within the first two days of inhaling a cigarette (n.p., 2007).  With symptoms of addiction (e.g., cravings, irritability, difficulty quitting) seen even in those who smoke only a few cigarettes per month.  Thus, confirming research “that [indicates] nicotine alters the structure and function of the brain” (para. 3).  Although nicotine is known to alter brain structure and function, the extrinsic, and intrinsic factors of nicotine addiction can stem from heredity and environmental factors making it difficult for someone to quit smoking.
Brain Structures and Functions
Using magnetic resonance imaging (MRI) to view the effects of smoking on brain structures and functions suggest a “reduction in volume and density of frontal gray matter, and cerebral atrophy” (Dodd, Chung, van den Broek, Barrick, Charlton, & Jones, 2012, p. 241).    Furthermore; Dodd, et. al., (2012) indicates mere exposure to cigarette smoke has been “associated with reduced microstructural integrity” (242).  Diffusion tensor imaging (DTI) studies reveal decreased molecule motility, resulting in tissue microstructural damage in aging white matter and cardiovascular disease.  Although researchers know little about how alterations of brain structure and function relate to smoking, Dodd, et. al., (2012) suggests the difference in white matter integrity and gray matter activation may account for the cognitive dysfunction (e.g., short-term verbal memory, reasoning, semantic fluency) associated with smoking, which increase with additional respiratory disorders and through increased pack-years of smoking.
Nicotine’s addictive properties affect mesotelencephalic brain sites by exerting dopaminergic actions that impede the determination of how rewarding something is; incentive values (Baker, Brandon, & Chasin, 2004).  This may account for the increased stimulation of the anticipation of smoking but not the smoking itself.
Extrinsic and Intrinsic Factors
The motivations for smoking are many: “physical dependence, ethnicity, impulsivity, affective disorder, and peer influences” are but a few (Baker, Brandon, & Chassin, 2004, p. 464).  Just as plentiful are the reasons to quit smoking; however, understanding the underlying causes of intrinsic and extrinsic motivations can enable someone to change his or her behavior.  Intrinsic behaviors create a positive self-concept, core belief, and enjoyment of an activity (e.g., smoking) and is developed over time with increased exposure.  Intrinsically motived behavior is often shared with friends and family and is associated with heightened excitement and a reduction in stress levels.  Extrinsic motivation is external to oneself, often beginning through small rewards, which gradually increase (e.g., trophies, grades, money, and recognition).  Of course, external rewards (or punishments) used to encourage or dissuade specific behaviors vary from person to person, and culture to culture.  The differences between intrinsic and extrinsic motivations are the reason or reasons for doing something.
 With smoking, the rewards for quitting can be difficult to identify.  For example quitting for health reasons can be both an intrinsic motivator (feeling better) and an extrinsic motivator (reduced illnesses and expense).  However, the level of addiction and behavioral characteristics of an individual may provide additional motivations of their own on the success of quitting smoking or not.  According to Lynskey, et. al., (1998) as restated by Baker, Brandon, & Chassin (2004), adolescence is a vulnerable time for tobacco dependency; those who are “‘uncontrolled’ and impulsive are also more likely to affiliate with substance-using peers” (p. 466).  As smokers age, health concerns increase and social desirability of smoking decrease, stimulating an intrinsic motivation to quit smoking, thus confirming that a new smokers belief in the negative consequences of smoking may not surface until years later.  However, tolerance and dependence create their own negative motivation with discontinuation or reduction of smoking (e.g., “dysphonia, anxiety, inability to concentrate, increased appetite, weight gain, sleep disruption, etc.” (Hughes, et. al., 1991; as restated by Baker, et. al., 2004, p. 471)). 
Heredity and Environmental Factors
Researchers have found that some individuals metabolize nicotine faster than others, which alter the brain’s response to smoking cues; citing nicotine receptor genes (CHRNA5, CHRNA3, and CHRNB4) that affect nicotine dependence and level of smoking.  Thus, exposure  to cigarettes causes nicotine concentration surges creating a desire or need, which motivates smoking; whereas, those with slow metabolizers maintain constant nicotine levels, which aid in attention, memory, and stress relief (Fitzgerald, 2012).  Rattue (2012) references Li-Shiun Chen, M.D., Washington University School of Medicine, who states:
“We found that the effects of smoking cessation medications depend on a person's genes.  If smokers have the risk genes, they don't quit easily on their own and will benefit greatly from the medications.  If smokers don't have the risk genes, they are likely to quit successfully without the help of medications such as nicotine replacement or bupropion" (para. 7).
These findings indicate that even the slightest exposure (e.g., parental smoking) to nicotine can activate the nicotine receptor genes that make smoking a rewarding behavior.  This information can enable scientist to fine-tune nicotine blockers, thereby decreasing these biological traits that increase the desire to smoke.  As with any addiction, changing the environmental cues that engage smoking behaviors is key.  Removing temptations by discarding any smoking related items from the home, vehicle, and work environment (cigarettes, lighters, and ashtrays), and washing clothing and bedding to remove the smells of nicotine.  Furthermore, avoiding others who smoke and smoking environments (e.g., pubs, parties, etc.) are helpful, especially within the first few days.  As indicated in a McGill University (2012) report “Smoking cues, such as the sight of cigarettes or smokers, affect smoking behavior and are linked to relapse and cigarette use” (para. 3).
Finding the motivation to quit smoking can offer many benefits; however, doing so can be a complicated maze of genetic and environmental factors as nicotine enables changes to brain structure and function creating both extrinsic and intrinsic motivation to create smoking behavior.  Thus as researchers identify which genes heighten smoking behaviors, biochemical support will enable individuals to quit smoking with fewer negative effects.  By blocking specific nicotine receptors, altered brain structure and function can be mitigated.  Although finding the motivation to overcome the negative effects of quitting smoking will require intrinsic and extrinsic support.  The human body is amazing; when someone quits smoking, the body begins to heal from the damage nicotine creates, thus the rewards of remaining nicotine free are improved health and improved quality of life lost because of smoking.

 

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