Substance Use & Misuse, 50:552–556, 2015 C 2015 Informa Healthcare USA, Inc. Copyright  ISSN: 1082-6084 print / 1532-2491 online DOI: 10.3109/10826084.2014.984851

ORIGINAL ARTICLE

Association Between Personality Disorders Traits and Problematic Cannabis Use in Adolescents Henri Chabrol, Tiffany Melioli and Nelly Goutaudier Universit´e de Toulouse – Le Mirail, Toulouse, France with higher frequency of drug use in adolescents (Hillege, Das, & de Ruiter, 2010). Schizotypal personality traits have been linked with adolescent cannabis use (Anglin et al., 2012). Histrionic, narcissistic, avoidant, schizoid, and passive–aggressive personality disorders have also been more rarely associated with adolescent substance abuse (e.g., DeMilio, 1989). Only one previous study examined the relative contribution of multiple personality disorder traits in adolescent cannabis use (Sussman, McCuller, & Dent, 2003): Among the 12 personality disorders evaluated with the Personality Disorder Questionnaire, antisocial and avoidant personality traits were the only traits associated with the frequency of cannabis use in the last 30 days. The aim of this study was to examine the relationships between the symptoms of problematic cannabis use and the personality disorder traits identified as associated with adolescent substance use by previous studies after controlling for the main psychopathological confounders, that is, anxious and depressive symptomatology which is common in adolescents and associated with a higher risk of substance use disorders (e.g., Rao et al., 1999). We hypothesized that personality disorder traits would be linked with problematic cannabis use symptoms above and beyond their associations with anxiety and depressive symptomatology.

Background: There are few studies on the contribution of personality disorder traits to cannabis use disorders in adolescents. Objectives: The aim of the study was to evaluate the association of personality disorder traits to problematic cannabis use. Methods: Participants were 111 high school students who completed self-report questionnaires, mainly the Cannabis Use Disorders Identification Test, assessing problematic cannabis use, and the Personality Diagnostic Questionnaire using the scales evaluating personality disorders most often linked to adolescent cannabis use. Results: A multiple regression analysis showed that personality disorder traits explained a high part of the variance in problematic cannabis use symptoms. Schizotypal and borderline personality traits were positively associated to problematic cannabis use symptoms after adjustment for anxious and depressive symptoms. Conclusions: This study suggests the importance of evaluating personality disorder traits in studies of risk factors or consequences of problematic cannabis use. Keywords problematic cannabis use, adolescents, personality disorders, schizotypal traits, borderline traits

Personality characteristics have been shown to demonstrate strong relations with substance use disorders and have been suggested as risk factors for the development of adolescent substance use, in particular sensation seeking (e.g., Donohew et al., 1999) and emotion regulation deficits (e.g., Zimmermann, 2010). Fewer studies have examined the role of personality disorders in adolescent cannabis use. Borderline personality disorder traits, characterized by instability of effects, identity, behavior, and relationships are the personality disorder traits having the greatest effects on the development of substance use disorder in adolescents (Cohen, Chen, Crawford, Brook, & Gordon, 2007). Antisocial personality traits are associated

METHOD Participants and Procedure

The sample comprised 111 students (54 boys; 57 girls; mean age of boys = 18 ± 1.2 years; mean age of girls = 17.2 ± 1.4 years) from four randomly selected classes in one randomly selected high school in Toulouse, France. Being free of charge, this public high school was not discriminatory on the basis of income and admitted

Address correspondence to Dr Henri Chabrol, Universit´e de Toulouse, Le Mirail, Pavillon de la recherche, 5 All´ees Antonio Machado, 31058 Toulouse cedex 9 31052, France. E-mail: [email protected]

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adolescents with diverse SES levels.1 They completed a consent form and anonymous questionnaires that were administered in classrooms by a Master’s level psychology student. The study procedures were approved by the ethics committee of the research ward and by the principals of the selected high schools. The study followed the ethical guidelines of Helsinki Declaration. No member of the school staff was present during the administration of questionnaires. The study was presented to students as an evaluation of the relationships between feelings, personality, and cannabis use in adolescence. Participants provided their willingness to participate through a consent form and no compensation was offered. The questionnaires were anonymous. None of the students declined to participate in the study. The subsample of cannabis users comprised 63 participants having used cannabis for a month or less during the last 6 months. Measures

Cannabis use was assessed using the French version of the Cannabis Use Disorders Identification Test (CUDIT) (Annaheim, Rehm, & Gmel, 2008; Guillem et al., 2011), which is a self-reported questionnaire of 10 questions that evaluate the cannabis consumption during the previous 6 months (How often do you use cannabis?) and identify problematic or harmful cannabis use (“How many hours were you ‘stoned’ on a typical day when you had been using cannabis?”; “How often were you “stoned” for 6 or more hours?”; “How often during the past 6 months did you find that you were not able to stop using cannabis once you had started?”; “How often during the past 6 months did you fail to do what was normally expected from you because of using cannabis?”; “How often during the past 6 months did you need to use cannabis in the morning to get yourself going after a heavy session of using cannabis?”; “How often during the past 6 months did you have a feeling of guilt or remorse after using cannabis?”; “How often in the past 6 months have you had a problem with your memory or concentration after using cannabis?”; “Have you or someone else been injured as a result of your use of cannabis during the past 6 months?”; “Has a relative, friend, or a doctor or other health worker been concerned about your use of cannabis or suggested you to cut down during the past 6 months?”). The first eight items are scored 0, 1, 2, 3, or 4, and the last two were scored 0 or 4. The total maximum score is 40. Compared with screening scales to assess problematic forms of cannabis use, the validity of the CUDIT score is satisfactory (Piontek, Kraus, & Klempova, 2008). Guillem et al. (2011) found a cut-off score of 10 for CUDIT when screening for problematic use. In the present study, Cronbach’s alpha was high (α = .90), indicating good internal reliability.

1

We cannot present more precise demographic characteristics, since principals of French high schools do not approve study procedures asking participants to give information on race, religion, or socioeconomic status. These areas are perceived as too sensitive. However, this contributed to the acceptability of the study.

Personality disorder traits were assessed with the French version of the Personality Diagnostic Questionnaire, Fourth edition (PDQ-4; Hyler, 1994; Bouvard, 2002). We used the borderline, antisocial, narcissistic, schizotypal, schizoid, avoidant, and passive–aggressive personality disorder scales. Anxiety and depression were controlled for using the Hospital Anxiety Depression Scale (HADS, Zigmond & Snaith, 1983). Cronbach’s alpha values and potential ranges are presented in Table 2. The internal consistency of most of the PDQ-4 scales was modest as reported in previous studies (e.g., Fossati et al., 1998). RESULTS

In the total sample, 70% of boys (n = 38, age = 18.1 ± 0.9 years) and 44% of girls (n = 25, age = 17.4 ± 1.3 years) reported having used cannabis at least once during the last 6 months (p = .07). Among cannabis users, the CUDIT total score was higher in boys than in girls (15.6 ± 7.3 vs. 8.8 ± 1.2, t = 3.5, p < .001). Frequency of use was higher in boys than in girls (Table 1). The proportion of users with problematic cannabis use (CUDIT scores ≥ 10) was higher among boys than girls (78% vs. 36%, p = .002). Problematic users had higher scores on schizotypal, borderline, antisocial traits, and depressive symptoms (Table 2). Correlations between personality traits and problematic cannabis use symptoms were presented in Table 3. Schizotypal traits had a higher correlation with problematic use symptoms. The association of personality traits to the CUDIT scores was tested with one multiple regression analysis, including all independent variables with covariates modeled simultaneously and conducted in the sub-sample of cannabis users. The independent variables were the scores of the scales assessing personality disorder traits and the anxiety and depression scores. The dependent variable was the CUDIT scores. The unique association of each independent variable was reported with standardized regression coefficient (β), p-value, and squared semi-partial correlation (sr2 ), which expresses the unique contribution of the independent variable to the total variance of the dependent variable (Table 4). The model explained 67% of the variance in the CUDIT scores. Schizotypal and borderline traits were positively associated with the CUDIT scores whereas schizoid traits were negatively associated with the CUDIT scores.

TABLE 1. Cannabis use frequency in the total sample

Never Monthly or less 2–4 times a month 2–3 times a week 4 or more times a week

Boys (n = 57)

Girls (n = 54)

p

33.3% 7% 12.3% 10.5% 36.8%

53.7% 18.5% 13.0% 3.7% 11.1%

.03 .07 .87 .001 .002

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TABLE 2. Comparison between cannabis users with and without problematic cannabis use Problematic users (n = 39)

Schizotypal traits Borderline traits Schizoid traits Histrionic traits Narcissistic traits Passive–aggressive traits Avoidant traits Antisocial traits HADS anxiety HADS depression

Non-problematic users (n = 24)

Cronbach’s α

Potential range

M

SD

M

SD

p

.68 .70 .52 .62 .70 .65 .76 .58 .83 .84

0–9 0–9 0–7 0–8 0–9 0–7 0–7 0–7 0–21 0–21

2.36 6.03 2.44 2.74 1.26 2.97 2.90 4.67 8.38 7.03

3.12 2.72 0.60 0.72 2.06 0.84 0.64 1.08 4.18 4.18

0.21 3.75 2.54 2.67 0.17 2.79 2.63 3.67 8.29 4.63

1.02 2.69 0.66 0.56 0.64 0.83 0.58 0.87 5.08 4.35

.002 .002 .51 .66 .01 .40 .09