Nicotine and Tobacco Dependence

Several instruments have been designed specifically for the purpose of assessing whether or not a smoker meets DSM-IV-TR or ICD-10 diagnostic criteria for nicotine dependence. Within a clinical context, such measures may be important for formulating a diagnosis and facilitating third-party reimbursement for treatment. This process is often accomplished in a fairly informal manner by simply reviewing each of the individual items with patients to determine whether they meet DSM or ICD criteria. Although structured diagnostic interviews have been designed for this purpose, they are not highly utilized outside of research settings because of their length and the time and training required to administer them. Health care providers typically prefer a quick and simple assessment of diagnostic criteria that can be administered in the context of a routine clinical encounter.

1.8.1 Minnesota Nicotine Withdrawal Scale

The most widely used measure of nicotine withdrawal is the Minnesota Nicotine Withdrawal Scale (MWS; Hughes & Hatsukami, 1986). The MWS is a brief measure of the presence and severity of 15 symptoms associated with nicotine withdrawal. Patients are asked to rate the severity of each symptom on a scale from 0 (none) to 4 (severe). To track changes accurately over time, patients should be instructed to complete the measure for several days prior to their quit attempt and then daily thereafter. Ratings should be made at the end of the day to reflect their experiences over the previous 24 hours. A copy of the Minnesota Nicotine Withdrawal Scale – Revised (Hughes & Hatsukami, 2005) is provided in Appendix 3.

1.8.2 Tobacco Dependence Screener

One useful measure that allows for a quick and straightforward assessment for the presence of nicotine dependence is the Tobacco Dependence Screener (TDS; Kawakami, Takatsuka, Inaba, & Shimizu, 1999). The TDS (see Appendix 4) is a 10-item measure designed to screen for nicotine dependence according to ICD-10 and DSM-IV-TR diagnostic criteria. Smokers are assessed for the presence or absence of 11 characteristic symptoms of nicotine dependence: smoking more than intended, desire to quit smoking, unsuccessful efforts to quit smoking, craving for tobacco, withdrawal symptoms, smoking to avoid withdrawal symptoms, smoking despite serious illness, smoking despite health problems, smoking despite mental problems, feeling dependent on tobacco, and forgoing important activities for smoking. The number of symptoms that are endorsed is then summed to arrive at a total score. A score of five or more symptoms has been shown to have maximal sensitivity and specificity for identifying those who meet the ICD-10 definition of nicotine dependence, whereas a cutoff of six or more symptoms is optimal when using DSM-IV-TR diagnostic criteria. The TDS performs well as a screening measure for nicotine dependence based on ICD-10 criteria and moderately well for DSM-IV-TR criteria. TDS scores are also correlated with other indices of tobacco use (e.g., expired-air carbon monoxide levels, number of cigarettes smoked per day, and years of smoking), and they have been shown to be pre dictive of the likelihood of quitting smoking.

1.8.3 Fagerström Test for Nicotine Dependence

The most widely used dimensional measure of nicotine dependence is the Fagerström Test for Nicotine Dependence (FTND; Heatherton et al., 1991). The FTND is a modified version of its predecessor, the Fagerström Tolerance Questionnaire (FTQ; Fagerström, 1978). The FTND is a brief, six-item measure that patients can complete quickly in the context of a clinical visit. In addition to assessing the average number of cigarettes smoked per day, the FTND also includes items to assess factors such as the time until smoking the first cigarette of the day, the tendency to smoke when ill, and difficulty in refraining from smoking in situations where it is not allowed. The individual items are presented in Appendix 5. Possible scores range from 0 to 10, with higher scores indicating greater levels of dependence. A score of = 6 is generally taken as indicating high levels of nicotine dependence.

1.8.4 Heavy Smoking Index

Although the FTND itself is quite brief, an even shorter dimensional measure of nicotine dependence is often desirable in busy clinical settings where time and resources are limited. Under those conditions, the Heavy Smoking Index (HSI; Heatherton, Kozlowski, Frecker, Rickert, & Robinson, 1989) may be preferable. Although most often used in epidemiological studies, the HSI can also be beneficial in a clinical setting for rapidly assessing nicotine dependence. The HSI comprises two items from the FTND: (1) The number of cigarettes smoked per day, and (2) The time after waking until the first cigarette of the day is smoked. These two items have been shown to have the greatest predictive value in terms of forecasting success with quitting smoking, which is why they are frequently used in place of the full FTND. Scores on the HSI correlate strongly with total scores on the FTND, with scores of 4 or higher on the HSI corresponding to a score of 6 or higher on the FTND.

1.8.5 Cigarette Dependence Scale

Another highly useful and empirically supported self-report measure of nicotine dependence is the Cigarette Dependence Scale (CDS; Etter, Le Houezec, & Perneger, 2003). The CDS is a 12-item measure that was designed to correspond more closely to DSM-IV-TR and ICD-10 criteria for nicotine dependence while also retaining features similar to those included in the FTND (see Appendix 6). As such, the CDS represents a hybrid approach to assessment that includes elements of both diagnostic and dimensional assessment models. Accordingly, the CDS includes items to assess the compulsion or urge to smoke, withdrawal symptoms, loss of control, allocating excessive amounts of time to smoking, neglect of other activities in favor of smoking, and persistence in smoking despite knowledge of the associated health risks.

Which measure is more useful? Each of the above described self-report measures has clinical utility for assessing nicotine dependence. The choice of measures is best determined based on the goals of the assessment. If the purpose is primarily to formulate a diagnostic impression, then the TDS or a clinical review of DSM-IV-TR or ICD-10 criteria are recommended. However, such measures typically do not provide an adequate index of severity of nicotine dependence across a continuous scale, nor is there good evidence to support their ability to predict severity of withdrawal symptoms or probability of relapse (Piper et al., 2006). The FTND and HSI have greater utility for predicting the probability of relapse and can be readily administered in a clinical setting. However, the reliabilities of the scales are suboptimal. Furthermore, while the FTND appears to be a good measure of the specific motivational aspects of nicotine dependence related to smoking in order to reduce withdrawal symptoms, it does not address or predict certain components considered to be central to dependence, such as the severity of withdrawal (Piper et al., 2006). The CDS – which combines features of continuous dependence severity scales such as the FTND and those designed to evaluate diagnostic criteria – possesses many of the advantages of both approaches to assessing dependence. The scale’s brevity, good reliability, and both construct and predictive validity are additional strengths. Furthermore, recent evidence suggests that the CDS may possess superior psychometric properties to the FTND, although additional confirmatory studies are needed. In addition, because the CDS is a new measure, data supporting its utility in predicting cessation in various samples are currently limited (Piper et al., 2006).