Assessment of smoking status, tobacco dependence and cue reactivity: Diagnostic tools for practice and for Implementation research

Assessment of smoking status, tobacco dependence and cue reactivity: Diagnostic tools for practice and for Implementation research Tobacco use is a major cause of death from cancer, cardiovascular disease, and pulmonary disease. Tobacco dependence is reported both in the fourth edition of Diagnostic and Statistical Manual of Mental Disorders and in the version 10 of World Health Organization’s International Classification of Diseases. Although nicotine plays a minor role, if any, in causing smoking-induced diseases, addiction to nicotine is the proximate cause of these diseases. Humans use addictive substances for a many reasons. They get pleasure, relief from pain/stress; they can enhance concentration, social behavior and reduce anxiety. Drug use may not be harmful for them or for their surrounding society, rather, it becomes chronic. Generally, smokers may need continuous intake of Nicotine to maintain their normal behaviour and satisfaction. Nicotine in cigarette smoke affects mood and performance. It meets the criteria of a highly addictive drug. It is a potent psychoactive substance with the reinforcing property and leads to nicotine withdrawal syndrome when it is absent. Nicotine is both a stimulant and a depressant. Nicotine dependence can be characterized by three phases (D’Souza and Markou, 2011) - acquisition and maintenance of nicotine-taking behaviour, withdrawal symptoms upon cessation of nicotine intake and vulnerability to relapse. The cigarette is a very efficient and highly engineered drug delivery system. By inhaling tobacco smoke, the average smoker takes in 1-2 milligrams of nicotine per cigarette. Oral use of smokeless tobacco (ST) products results in high venous concentrations of nicotine similar to tobacco smoking. Within 10 minutes after administration of a smokeless tobacco product, 10ng/ml of Nicotine can be delivered (Holm et al. 1992). Recent research has revealed that Acetyl Choline receptors play a critical role in developing nicotine addiction, and nicotine addiction is a dynamic process including different stages such as nicotine-induced reward, tolerance, dependence and withdrawal-relapse symptoms. Increases in dopamine levels within the mesolimbic system give rise to rewarding effects. Two types of pharmacological therapies have been approved and are now licensed for smoking cessation. The first therapy consists of nicotine replacement therapy (NRT), substituting the nicotine from cigarettes with safer nicotine formulations. The second therapy is bupropion, an antidepressant of the amino ketone class, which has been demonstrated to be effective in smoking cessation. Varenicline is the only FDA-approved smoking cessation agent at present, that was rationally designed through traditional drug discovery processes based on its action as an α4β2* nAChR partial agonist (Coe et al., 2005; Dwoskin et al., 2009; Lerman et al., 2007; Reus et al., 2007). Along with the progress of pre-clinical and clinical research regarding Nicotine addiction, the measurement of Nicotine addiction (through tobacco smoking and smokeless tobacco) has been recognized as an important issue. Assessment of Nicotine dependence is a hypothetical construct that is designed to explain and predict societally important outcomes, such as an inability to quit smoking, heavy use, and other problems occasioned by smoking or tobacco use (Piper et al., 2006). The common scale used for the assessment of tobacco smoking is the Fagerstrom Test for Nicotine Dependence (FTND). Recently, it was renamed as Fagestrom Test for Cigarette Dependence (FTCD), as the FTCD uses criteria that are specific to the Nicotine and the cigarette. A number of other scales to measure dependence have been developed, but they are not widely used in nicotine dependence research. These include the substance disorder section of Composite International Diagnostic Interview (CIDI) and Tobacco Dependence Screener (TDS), the Cigarette Dependence Scale (CDS) and the Hooked Nicotine Checklist (HONC). Ebbert et al., (2006) adopted the Fagerstrom Test for Nicotine Dependence (FTND) (Heatherton et al., 1991) and modified it for use in ST users. Further, IARC handbook (volume 13) released from WHO, indicated that, although less research has been done to validate self-report measures of ST-induced nicotine dependence, questionnaires derived from FTND appear to provide a means for identifying ST users who are nicotine dependent. Drug addiction does not occur overnight, but takes years to develop, and indeed is hypothesized to be learned. Drug use begins by learning that the substance is rewarding due to powerful interoceptive effects, thus increasing the desire to use the drug again. Over time certain cues in the environment become associated with drug use until the cues alone are sufficient to stimulate desire or craving for the drug (Torregrossa et al., (2011). Environmental stimuli are embedded within every level of a smoker’s memory of tobacco. Vulnerability to nicotine dependence varies from one individual to other. This variation could be used for the development of theoretical models of dependence and for research into both prevention and treatment of nicotine dependence (Donny et al., 2008). Exhaled carbon monoxide (CO) is the most rapid, non-invasive, and easily measured biochemical indicator of smoking (Marrone, 2010). Many studies have used exhaled CO as a biological indicator to assess smoking status and to evaluate nicotine dependence. Two issues have been addressed for this thesis work: 1. Developing a package of diagnostic tool to classify Nicotine and Tobacco dependence for individual tobacco smoker/ smokeless tobacco user which can be utilized for clinical tobacco cessation purpose. 2. Developing an assessment scale to predict the risk environment of tobacco smoke/smokeless tobacco for clinical use at tobacco cessation centres. Considering the above said issues, the aim of the present study is to provide a daily support to the psychologist/physician to improve the quality and the success rate of the tobacco cessation treatment in the future and, in perspective, to design tools (cue reactivity assessment) for an early assessment of risk to relapse of smoking. After getting the informed consent from the subjects, the demographic profile questionnaire was filled in by the subjects or assisted. After identifying the subjects as tobacco smokers or smokeless tobacco users or dual users, the smokers were asked/ assisted to fill in the smoking history profile, FTND and cue reactivity questionnaire. Whereas the smokeless tobacco users were asked /assisted to fill in the tobacco use profile, FTND-ST and cue reactivity questionnaire, Dual users filled both FTND and FTND-ST questionnaire and gave responses to cue reactivity questionnaire with respect to both tobacco smoking and smokeless tobacco use. The exhaled CO was measured for tobacco users with the help of Smokerlyzer®, a device used to measure CO in lungs as parts per million (ppm). Majority of the smokers found very difficult to give up the first cigarette in the morning. Higher percentages of smokeless tobacco users place their first dip within five minutes after they wake up in the morning. Smokeless tobacco users showed higher dependence than tobacco smokers. Both showed less craving in restricted condition within all the three risk situations (after having breakfast, after having lunch/dinner at home, after having lunch/dinner at restaurant). Craving differences were found to be high between the smoking environment (other people smoking vs. no other people smoking). No difference in the craving was observed in the social condition (with others vs. alone). This is a practical evidence of cue elicited craving in accordance with previous lab experiments on cue reactivity. There are no recently published data about the smoking and smokeless tobacco use or cessation outcome information in Sudan. No possible estimation on sample size of the smokers could be given as the present study is the first of its kind to initiate the assessment of tobacco smoking, smokeless tobacco and the craving due to tobacco related and non-related factors. This was accomplished using a package of standard questionnaires. The objective of this study was to make use of the demographic information, tobacco use status, Nicotine dependence measurement scales as a diagnostic tool to predict the individual variations in the smokers and the smokeless tobacco users who approached the tobacco cessation center. This was achieved by the use of standard questionnaires like demographic profile questionnaires, Smoking status information profile, Fagestrom Test for Nicotine Dependence (FTND) and Fagerstrom Test for Nicotine Dependence – Smokeless Tobacco (FTND-ST). With a step ahead, the study further aimed to use measuring scale designed in our lab to predict the risk environment associated with the tobacco use in each individual. The demographic information and the tobacco smoking profile shows that the tobacco smokers are mild smokers and almost half of them are living with the other smokers in their family. The FTND scale used to measure the dependence shows that the tobacco smokers are low dependent who are willing to quit immediately, but does not show longest period of self-reported abstinence or higher quit rate. The relationship between the use and dependence shows that, more the cigarette use, higher the dependence and more the CO level exhaled from the lungs. As hypothesized, craving level obtained by tobacco smokers differ in different conditions across situations. In the smoking environment, they have expressed more craving in smoking available condition than in no availability condition. Most of the Smokeless tobacco users have initiated their chewing habit less than 15 years and 80% of them live with other ST users. FTND-ST scale shows that smokeless tobacco users are highly dependent to Nicotine and they high withdrawal to Nicotine. Similar to tobacco smokers, smokeless tobacco users have shown to be induced by the tobacco available environment, as they have scored a significant Likert score in cue reactivity assessment, when compared to other conditions. Dual users are more dependent to smokeless tobacco than tobacco smoking. Tobacco smokers have shown higher craving to smoke immediately after breaking the Ramadan fasting in sun set time. Smokeless tobacco users show same level of craving to tobacco during Ramadan fasting day and immediately after breaking the fast in the sun set time. This activity of transfer from research to practice at a tobacco cessation clinic could increase the efficacy and reduce the costs of intervention, thus improving the reliability of treatment. In the meantime, generated in-progress data could be used for further research and thus practice implementation. This low-cost, medium-term investigation, is a basic research that would help smokers to survive in their environment at risk of relapse, and thus to comply with intervention. Further research is needed to focus on the use of the same set of dependence measures and cue reactivity scales at regular basis during the cessation treatment to study the effect of the diagnostic tools employed.