Impulsivity In SUD Research

Impulsivity plays a crucial role in the understanding and diagnosis of many psychopathologies including Substance Use Disorder (SUD). Therefore, careful measurement of impulsivity is of great importance to researchers and clinicians studying SUD. The objective of this essay was to critically evaluate the efficacy and relationship between three common self-report measures of impulsivity in SUD research and diagnosis. This paper highlights the different definitions of impulsivity used within each of these scales and assesses whether they are measuring the same construct. Research revealed that BIS-11, I7 and BIS/BAS scales are highly correlated with each other, indicating that despite their differences in definitions all of these scales are

measuring the same construct of impulsivity. Different applicants and psychometric properties of these scales were discussed. It was found that BIS-11 was more extensively researched both in different populations and cross-culturally. Advantages and disadvantages of self-report measures and future research options are also discussed.

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In recent years, there has been a significant increase in the amount of research on impulsivity. One of the reasons for this is that impulsivity is a prominent dimension of several DSM-V disorders (Meda et al., 2009). It can be defined as an inability to delay gratification to attain immediate rewards, lack of forethought and failure to inhibit inappropriate behaviours (Patton & Stanford, 1995; Paine, Dringenberg & Olmstead, 2003, Reynolds, Ortengren, Richards & Wit, 2005). Moreover, impulsivity also plays a crucial role in understanding and diagnosing various forms of psychopathy, including aggression, conduct disorder and most importantly Substance Use Disorder (SUD) (Lane, Cherek, Rhoadess, Pietras & Tcheremissine, 2003). Research to date has provided a wealth of empirical evidence to associate impulsivity to risk for substance abuse and dependence. Many studies have found drug users including, smokers, alcoholics, and cocaine users score higher on self-report measures of impulsivity (Dawe & Laxton, 2004; Slater, 2003; Tercyak & Audrain-McGovern, 2003). To conduct appropriate research and diagnosis for SUD, careful measurement of impulsivity is very important. Although numerous instruments available to measure impulsivity in SUD, there are a number of differences in how these instruments operationalise impulsivity (Lane et al., 2003). The purpose of this paper is to critically examine the efficacy and the relationship between three self-report measures of impulsivity [Barratt Impulsiveness Scale (BIS-11) (Patton & Stanford, 1995), Eysenck Impulsiveness Scale (I7) (Eysenck, Pearson, Easting & Allsopp, 1985) and the Behavioural Inhibition/Activation Scale (BIS/BAS) (Craver & White, 1994)] commonly used in SUD research and diagnosis.

The most-common way of measuring the construct of impulsivity is via self-report questionnaires; as they assess general behaviour over time as well as trait levels of behaviour.

They are particularly useful when the participant has insight into their own feelings, behaviour and thoughts (Cyders & Coskunpinar, 2011). The BIS-11 is the most commonly used self-report measure of trait impulsivity in SUD research (Patton & Stanford, 1995). In BIS-11, impulsivity is conceptualised as a tendency to respond to internal or external stimuli in a reckless fashion without any consideration to the consequences (Patton & Stanford, 1995). BIS-11 includes 30-items, with three subscales-motor impulsivity (acting without thinking), cognitive impulsivity (making fast cognitive-decisions) and non-planning impulsivity (lack of concern about the future) (Patton & Stanford, 1995; Stanford et al., 2009). The second most-widely used scale for studying impulsivity in SUD is I7. It includes 54-items and incorporates the risk-taking dimension of impulsivity in its measurement. I7 defined impulsivity as a characteristic of people who act on the spur of the moment without being aware of the risk involved (Eysenck, Pearson, Easting & Allsopp, 1985). It consists of three subscales; Impulsiveness (behaving without thinking and considering consequences), Venturesomeness (unnecessary risk-taking) and Empathy (Miller, Joseph & Tudway, 2004). The last scale commonly used to measure impulsivity in SUD research

is the BIS/BAS. BIS/BAS scale was developed by Carver and White (1994) based on Gray’s (1970) bio-psychological theory of personality, which identifies two dimensions of personality-impulsivity and anxiety. The BIS is a neuropsychological system that predicts an individual’s response to anxiety-relevant cues in a given environment and is associated with sensitivity to punishment. In contrast, BAS is based on the premise of appetitive motivation, i.e. an individual’s motivation to pursue and achieve goals and related with trait impulsivity (Simons, Dvorak & Lau-Barraco, 2009). As this essay is in regards to impulsivity, only the BAS scale was reviewed. The BAS scale is divided into three subscales- Fun seeking, Reward Responsiveness and Drive and it measures impulsivity (Miller et al., 2004).

All three of these scales strive to measure the influence of impulsivity in SUD. However, the apparent difference in how impulsivity is operationalised within each of these scales is a major area of concern. Because of its implications is SUD and other psychopathologies, it is of utmost importance to clarify whether, despite the obvious differences in definitions, all three of these scales are measuring the same construct or just a narrow facet of impulsivity. One way to access the underlying similarities between these scales is by exploring the relationship between these scales and their subscales. The few studies that have assessed the overall relationship between BIS-11, I7 and BIS/BAS, have found them to be highly correlated (Miller, Joseph & Tudway, 2004; Stanford et al., 2009). In addition, Stanford and associates (2009) found that the impulsiveness subscale in I7 was highly positively correlated (r values between.40 to .60) with all three subscales (motor, cognitive and non-planning impulsivity) of BIS-11. This finding indicates that, despite their differences in names and definitions, BIS-11 and I7 are essentially measuring the same construct. Similar results were found by Miller, Joseph and Tudway, (2004) in regards to overall correlations between BIS-11, I7 and BIS/BAS. However, after conducting extensive principle component analysis, they also found a very weak correlation between the reward responsiveness subscale of BIS/BAS and the subscales of I7 and BIS-11 (Miller, Joseph & Tudway, 2004). Consequently, these results indicate that the reward-responsiveness scale of BAS is either measuring a very narrow facet of impulsivity or not adequately measuring any facet of impulsivity. However, it is also worth noting that this study used snowballing sampling technique and only recruited participants from the UK, which may have resulted in a non-homogenised sample.

Additionally, some other areas where is these scales differ are-sensitivity to measuring impulsivity and their different applications. For instance, Dom, D’haene, Hulstijn, and Sabbe (2006) found that early-onset alcoholics scored higher on the BIS-11 in comparison to late-onset alcoholics, which are considered less severe cases. However, this level of sensitivity is not visible is I7 and BIS/BAS. Moreover, although BIS-11 has predominately been used in SUD research and diagnosis, it is also a well-established measurement tool for other disorders, including, Depression, ADHD and Bipolar disorder (Stanford et al., 2009). Furthermore, unlike I7 and BIS/BAS, BIS-11 is also extensively used to measure impulsivity in various forensic populations (violent offenders with Schizophrenia and Borderline Personality Disorder (BDP) (Enticott, Ogloff, Bradshaw, Fitzgerald; 2008; Kirkpatrick et al., 2007). Additionally, BIS-11 has also been translated and successfully administered in 11 different nations (Japan, German, Hebrew) (Stanford et al., 2009) and therefore it can be quite easily be generalized to a normal population.

Psychometric properties of these tests are another area of discussion. As the oldest and most widely used test for impulsivity, the overall validity and reliability of BIS-11 are well established in the literature. Many studies have provided excellent data for internal consistencies for the three subscales of BIS-11 (alpha coefficient between.89 to.92) (Lejuez et al., 2002; Pietras & Tcheremissine, 2003; Stanford et al., 2009). Additionally, in a comprehensive study analysing BIS-11 scale, Stanford and associates 2009 found BIS-11 had excellent test-retest reliability at one month ( .83). However, these properties are not as well researched for the other two instruments. I7 and BIS/BAS scales have both shown to have good internal consistencies, both overall and at a subscale level (between .80 to.85 and .70 to .80 respectively) (Miller, Joseph & Tudway, 2004; Luengo, Carrillo-De-La-Peña & Otero, 1991). However, few studies have analysed how consistent these results are over time. In terms of validity, all three scales demonstrate high levels of overall construct validity i.e. they measure what they claim to be measuring (Stanford et al., 2009). However, as mentioned before, the reward responsiveness subscale of BIS/BAS may be measuring a narrow facet of impulsivity rather than general impulsivity (Miller et al., 2004). Aforementioned, Miller, Joseph and Tudway also found strong correlations between BIS-11, I7 and BIS/BAS, further indicating convergent validity across all three instruments.

Although, all of the scales mentioned above are reliable and valid, there are some general disadvantages in using self-report measures, like social-desirability.

Social-desirability is when participants give answers on questionnaires they deem socially acceptable rather than answers that truly reflect their personality and this phenomenon can sometimes act as a confounding variable (McDonald, 2008; Paulhus & Vazire, 2007). Aforementioned, self-report measures only analyse an individual's general behaviour over-time, not their response in particular situation. Therefore, to measure this type or state-like impulsivity, behavioural or laboratory measures are required (Reynolds, Ortengren, Richards & Wit,

2005).

To summarise, the objective of this essay was to critically evaluate the efficacy and relationship between three common self-report measures of impulsivity in SUD research and diagnosis. It highlights the differences in operationalised forms of impulsivity within each of these scales. Research revealed that BIS-11, I7 and BIS/BAS are all highly correlated with each other, i.e. they are all measuring the same general construct of impulsivity. However, it was also found that the BIS-11 scale is much more comprehensively researched in comparison to I7 and BIS/BAS. Apart from SUD research and diagnosis, BIS-11 is also extensively used in research of a number of other psychological disorders. Moreover, in comparison to I7 and BIS/BAS, it’s efficacy is also well-established, cross-culturally and in various forensic populations. Among these three measures of impulsivity, BIS-11 is clearly the more reliable, well-researched and efficacious tool to measure impulsivity. Similarly, although I7 and BIS/BAS are very reliable and valid measures of impulsivity, future research in regards to different applications and populations would be very beneficial to researchers and clinician interested in studying influences of impulsivity in different areas.