Levels of impulsivity in individuals with cannabis use disorder

Abstract Introduction Substance use disorder consists of the presence of cognitive, behavioral, and physiological symptoms, indicating continuous use of one or more substances by the individual. The literature points to the existence of a relationship between impulsive behavior, in which individuals tend to act thoughtlessly and with a lower level of planning, and consumption of substances including cannabis. Objectives To examine the presence and severity of impulsivity in individuals with cannabis use disorder and investigate associations between sociodemographic and clinical characteristics and impulsivity. Method Participants completed a sociodemographic data sheet and the Barratt Impulsiveness Scale (BIS-11). A total of 122 subjects with a diagnosis of cannabis use disorder participated, with a mean age of 34.46 years (standard deviation = 9.62). Results The prevalence of high levels of impulsivity in the sample ranged from 30 to 33%; the BIS-11 total score was significantly associated with cohabitation and alcohol use. The BIS-11 scores for motor impulsivity and attentional impulsivity were also associated with consumption of alcohol. No associations were found between impulsivity and the variables age, education, use of tobacco, or use of cocaine/crack. Conclusion This study contributes to understanding of substance dependence, especially cannabis. It found presence of impulsive behavior among individuals with cannabis use disorder, which is corroborated by reports in the literature.


Introduction
Substance use disorder is related to presence of a set of cognitive, behavioral, and physiological symptoms that indicate continuous use by the individual, despite the substance-related problems. 1 Dependence is increased by the individual's continuous and long-lasting exposure to the substance, accumulating psychological, neurobiological, and social factors. 1 According to the United Nations Office for Drugs and Crime (UNODC), the use of Cannabis sativa, also known as marijuana or cannabis, has increased in several parts of the world, 2 ranking it as the third most consumed substance in the world, after alcohol and cigarettes. [2][3][4] Cannabis is also the illicit substance most consumed in Brazil and 3.2% of the Brazilian population have used psychoactive substances, which equates to 4.9 million people. 4 Reported rates of use are higher in men than in women and use is more common between 18 and 29 years of age and less common from 65 years onwards. 5 The literature reports that it is common for individuals who use substances to have comorbidities such as depressive and anxiety disorders, among others, with emphasis on impulsive behaviors. [4][5][6] Impulsive behaviors can be considered a broad phenotype with varied and peculiar characteristics, presenting distinct types of behaviors and cognitive expressions. 6 Despite their multifaceted character, they are identified as rapid behaviors, performed without assessment of the context and linked with difficulty in controlling the response.
In turn, impulsiveness is related to such behaviors and impulsive individuals tend to act thoughtlessly and with a lower level of planning. 7 Impulsiveness negatively affects the individual and people around them 8 and is associated with use of substances. 9 An investigation into the impulsive behavior of psychoactive substancedependent individuals, using the Barratt Impulsiveness Scale (BIS-11), 8

Instruments
The instruments used were as follows: 1) sociodemographic data sheet, to collect the main data on participants; 2) structured clinical interview that covered history of substance use and morbidities. The to 84 years old, allowing determination of occurrence of impulsivity impairments both for the general score and for the three factors of the scale. In this study, the alpha value for the BIS-11 general score was 0.823, while alpha for the motor impulsivity factor was 0.650, alpha for attentional impulsivity was 0.703, and alpha for impulsiveness due to lack of planning was 0.623.

Ethical approval
The study was approved by the research ethics committee at Faculdade Meridional (IMED; CAAE 43367620.8.0000.5319) and was conducted in accordance with the Declaration of Helsinki. The researchers guarantee that individuals provided written consent and that all documentation will be kept confidential.

Data analysis
Statistical analysis was conducted using the  As for the data on substance use, most of the participants also used other substances, such as alcohol, tobacco, and cocaine/crack, in addition to cannabis. data in addition to total scores classified by percentiles.

Results
For the total BIS-11 score, from 30 to 33% of the participants reported impulsivity levels classified as deficits, based on the z score cutoff of ≤ -1.50, and percentiles greater than or equal to 90, respectively.
Regarding factors, and based on the same benchmarks, motor impulsivity was the factor with highest percentage of deficit(37% by z score; 43% by percentile), followed by attentional impulsivity (24% by z score; 26% by percentile), and impulsivity due to lack of planning (21% by z score; 26% by percentile). In relation to factor scores, impulsivity due to lack of planning had the highest score, with a mean of 27.93 (SD = 5.9). Table 3 shows the chi-square analysis of associations between sociodemographic variables, substance use (alcohol, tobacco, and cocaine/crack), and presence of impulsivity according to the BIS-11 score and classification based on z scores. The BIS-11 total score was significantly associated with the variable cohabitation and alcohol use. This result suggests that adults who live alone and consume alcohol together with cannabis tend to report higher rates of impulsivity.
The scores for the BIS-11 motor impulsivity and attentional impulsivity factors were also significantly associated with alcohol consumption. This suggests that individuals with cannabis use disorder and those who also use alcohol report greater impairment in their ability to inhibit responses and lack of focus when performing tasks. No associations were found with age, education, tobacco use, or cocaine/crack use.

Discussion
The main objective of this study was to examine presence and severity of impulsivity in individuals diagnosed with substance use disorder, specifically users of cannabis. Therefore, the performance of participants on the BIS-11 scale was validated and normative data for the Brazilian context were classified based on z scores and percentile rankings. The prevalence of high impulsivity scores found in the sample of this study ranged between 30 and 33%, depending on the classification adopted (z score or percentile).
When it comes to the BIS-11 factors, the motor impulsivity factor reported the highest percentage of impairment among participants (37% by z score; 43% by percentile). Another objective of this study was to test for associations between sociodemographic and clinical characteristics (age, education, marital status, cohabitation, and use of other psychoactive substances) and impulsivity. Participants who live alone and consume alcohol together with cannabis tend to exhibit more impulsive behaviors. In addition, the occurrence of high levels of motor and attentional impulsivity was also associated with alcohol consumption.
The prevalence of problems of impulsivity in the study sample exceeded the levels expected for the population at large (approximately 17%), 15,16 although no specific values were found for the clinical population with substance use disorder, mainly related to the use of cannabis. However, high levels of impulsivity were found in college students who use cannabis. [17][18][19] This finding supports the results found in literature, according to which presence of impulsive behaviors is very common in several disorders, 5 such as in substance use disorder. 5,9,16 It highlights the existence of a direct linkage between impulsivity and dependence on psychoactive substances. 1 Findings are also in line with other studies that also found impaired self-control of aggression among cannabis users. 10,11 This result reinforces a trait of impulsivity in individuals with cannabis use disorder and difficulty in dealing with criticism from others. In adverse situations, they may react with poor control of anger and aggression. These behaviors may trigger more impairments in their interpersonal relationships.
In line with this study's findings, the literature confirms that prevalence of substance use disorder is higher among men. 5 Despite the higher prevalence of participants in the age group of 30 to 62 years, the mean age found in the sample bears out DSM-5 5 studies affirming that use among middle-aged adults and the elderly is increasing. Rather et al. 17 and Goodman et al. 18 also reported similar ages for the profile of adults using cannabis. In this study, however, there was no association between higher levels of impulsivity and age, although it has been observed that impairments in executive components, including impulsivity, arising from the use of cannabis were more frequent among adolescents in comparison to adults. 19 Still regarding sociodemographic characteristics, Another study with patients hospitalized due to use of substances found that most participants reported using multiple substances such as cannabis, alcohol, and crack/cocaine. 24 The results of this study suggest that adults living alone and consuming alcohol jointly with cannabis tend to report higher rates of impulsivity. Data in the literature suggest that use of several psychoactive substances is associated with changes in levels of impulsivity 1,25 and can be related to family conflicts. 26