- Email: [email protected]
Cannabis use and delinquent behaviors in high-school students
Addictive Behaviors 34 (2009) 187–189
Contents lists available at ScienceDirect
Addictive Behaviors
Cannabis use and delinquent behaviors in high-school students Henri Chabrol ⁎, Carine Saint-Martin Université de Toulouse-Le Mirail, France
a r t i c l e Keywords: Cannabis use Delinquency Psychopathic traits Borderline traits Depressive symptoms Adolescence
i n f o
a b s t r a c t The aim of the study was to evaluate the relative contributions of cannabis use, alcohol use, psychopathic and borderline personality traits, and depressive symptoms in the prediction of delinquent behaviors. Participants were 312 high-school students who completed self-report questionnaires. Hierarchical multiple regression analyses were conducted to investigate the contribution of cannabis use and potential confounding variables to delinquent behaviors in the total sample and in cannabis users. Cannabis use was no more a significant independent predictor of delinquent behaviors after adjustment for alcohol use and psychopathological variables. However, among users, frequency of use remained a significant predictor of delinquency after adjustment for those confounders. © 2008 Elsevier Ltd. All rights reserved.
Cannabis use and delinquency tend to co-occur among adolescents. Delinquent behavior is associated with a multitude of risk factors including psychological, family, peer, and school variables which are also associated with cannabis use. A few crosssectional or longitudinal studies have shown that controlling for confounding risk factors such as family disadvantage or alcohol use weakened or eliminated the association between cannabis use and delinquent behavior (McGee, Williams, Poulton, & Moffitt, 2000; Fergusson, Horwood, & Swain-Campbell, 2002; Monshouwer et al., 2006). However, none of these studies have adjusted for depressive symptoms or personality disorder traits such as psychopathic or borderline traits which are frequent among adolescents and may contribute to both delinquent behaviors and cannabis use (Chabrol, Ducongé, Casas, Roura, & Carey, 2005; Chabrol, Montovany, Chouicha, Callahan, & Mullet, 2001; Frick, Cornell, Barry, Bodin, & Dane, 2003; Rey, Sawyer, Raphael, Patton, & Lynskey, 2002; Rittakalio, Kaltiala-Heino, Kivivuori, & Rimpelä, 2005). The aim of our study was to evaluate the contribution of cannabis use to the prediction of delinquent behaviors after controlling for alcohol use, psychopathic and borderline traits, and depressive symptoms. This is an important topic given the high frequency of cannabis use among adolescents. In France, a nation wide survey showed that 50% of boys and 40% of girls have used cannabis at least once during the past year (Choquet et al., 2004). 1. Methods Data was obtained from students attending two randomly selected high schools in Toulouse, France. Eleven classes were randomly drawn from these high schools. The sample consisted of 312 students (157 girls, 155 boys; mean age = 16.6 ± 1.4; age range = 14–22). Being free of charge, these public high schools were not discriminatory on the basis of income and admitted adolescents with diverse SES levels. This sample, however, is not guaranteed to be representative of the general population of French adolescents. The questionnaires were administered in the classroom by a Master's level psychology student who presented the study and collected the questionnaires. No members of the school staff were present during the administration of the questionnaires. Participants placed completed questionnaires in a sealed envelope. The questionnaires were anonymous, and therefore students were assured that their responses were confidential. Students were informed that participation was voluntary and signed a consent form. No compensation was offered. No student declined to participate in the study. ⁎ Corresponding author. 21 rue des Cèdres, 31400 Toulouse, France. Tel.: +33 561 22 52 90; fax: +33 561 50 39 92. E-mail address: [email protected] (H. Chabrol). 0306-4603/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.addbeh.2008.10.005
188
H. Chabrol, C. Saint-Martin / Addictive Behaviors 34 (2009) 187–189
Delinquent behaviors, alcohol and cannabis use, and psychopathological variables were assessed with self-report scales that had been devised to be used in community samples. Delinquent behaviors were assessed with the Antisocial Behavior Scales (ABS, Schawb-Stone et al., 1999) which include three subscales assessing behavior problems of different severity: 1) conduct problems assessing relatively mild behavior problems, 2) less severe delinquency assessing non-violent antisocial behavior, 3) severe antisocial behavior exploring relatively serious aggressive and antisocial behavior. The respondents are asked to report on a 5-point scale how many times (ranging from “0 times” to “5 or more times”) they were involved in the described behaviors during the past year. In this study, only the two subscales assessing less severe delinquency and severe antisocial behavior were used. The ABS contain one item on alcohol use and one item on cannabis use. To avoid spurious associations, scores were computed without those items. The eight remaining items provide a total sum score that can range from 0 to 32. In this sample, coefficient alpha for those items was 0.78. Alcohol use was assessed with the item of the ABS exploring being high at school after drinking alcohol. Cannabis use in the past 6months was assessed with the 9-point rating scale used by Simons, Correia, Carey, and Borsari (1998) ranging from 0 (no use) to 8 (more than once a day). This scale allowed defining two variables, frequency of use and cannabis use in which use was dichotomized into ‘no use in the last six months’ and ‘use at least once in the past six months’. Psychopathic traits were assessed using the 50-item Youth Psychopathic traits Inventory which was developed for youth ages 12 and older (YPI; Andershed, Kerr, Stattin, & Levander, 2002). Items are worded to assess psychopathic features indirectly. Psychopathic features are framed as characteristics that should seems neutral or even appealing to those with psychopathic traits (e.g. “I usually feel calm when other people are scared”) in order to reduce social desirability response bias. The YPI was validated with a community sample of adolescents. The YPI showed good internal consistency, test–retest reliability and convergent and predictive validity (Andershed et al., 2002). Borderline personality disorder traits were assessed using the 24-item Borderline Personality Features Scale for Children (BPFS-C; Crick, Murray-Close, & Woods, 2005). This scale assesses the core dimensions of borderline personality disorder, affective instability, identity problems, negative relationships, and self-harm. The BPFS-C showed good internal, construct and discriminant validity (Crick et al., 2005). Depressive symptoms were assessed using the Center for Epidemiological Studies—Depression scale (CES-D; Radloff, 1977). The CES-D has been widely used with adolescents as its brevity, format, internal reliability, and concurrent validity are considered to be attractive (Myers & Winters, 2002). The CES-D is composed of 20 items assessing depressed mood, feelings of worthlessness, feelings of hopelessness, feelings that others are hostile or rejecting, psychomotor retardation, loss of appetite, and sleep disturbance. In this sample, coefficient alphas for these three scales were 0.91, 0.82, and 0.89, respectively. A hierarchical multiple regression analysis was conducted to investigate the contribution of cannabis use and potential confounding variables to delinquent behaviors in the total sample. Among cannabis users, a hierarchical multiple regression analysis was performed to assess the contribution of frequency of use. The participants-to-predictors ratio was adequate for multiple regression analysis as it was greater than the traditional guideline of at least ten participants per predictor (Howell, 1997). The proportion of the variance in delinquent behavior explained by the predictors was reported with the multiple R2. The significance of R2 was evaluated by a F statistic. The unique contribution of each predictor was reported with standardized regression coefficient (β), t statistic and p value. All predictor variables had tolerance values N0.4 excluding multicollinearity. All statistical analyses were performed using STATISTICA, Version 8. 2. Results In the total sample, 55% of boys (n = 85) and 24% of girls (n = 37) reported at least one delinquent behaviors during the past year (p b0.0001). Boys reported a greater number of delinquent behavior than girls (2.7 ± 4.2 vs 0.77 ± 2.3, t = 5.1, p bb0.0001). Thirty five
Table 1 Hierarchical multiple regression analyses predicting delinquent behaviors Total sample (N = 312) 2
F
R
Step 1 Sex Age Cannabis use (in the total sample) or Frequency of use (among cannabis users)
13.1 ⁎
0.11
Step 2 Sex Age Cannabis use (in the total sample) or Frequency of use (among cannabis users) Alcohol misuse Psychopathic traits Borderline traits Depressive symptoms
14.6 ⁎
⁎ p b 0.001.
β
Cannabis users (n = 97) t
p
−0.11 0.05 0.18
−1.87 0.88 3.36
0.06 0.38 0.0001
−0.10 0.03 0.04
−1.77 0.61 0.76
0.08 0.54 0.45
0.19 0.35 0.01 −0.06
3.51 5.52 0.20 −1.00
0.001 b0.0001 0.84 0.32
F
R
5.4 ⁎
0.15
5.1 ⁎
0.25
2
β
t
p
− 0.20 − 0.11 0.28
− 1.86 − 1.04 2.50
0.07 0.30 0.01
− 0.03 − 0.11 0.23
− 0.28 − 1.12 2.06
0.78 0.27 0.04
0.22 0.38 − 0.15 0.003
2.28 3.43 − 1.04 0.02
0.02 0.001 0.30 0.98
0.29
H. Chabrol, C. Saint-Martin / Addictive Behaviors 34 (2009) 187–189
189
percent of boys (n = 54) and 27% of girls (n = 43) reported having used cannabis at least once during the last 6months (p = 0.13). Among cannabis users, boys reported a greater frequency of use than girls on Simons et al.'s rating scale: average use for boys was once or twice per week whereas average use for girls was once a month (4.2 ± 2.7 vs 2.1 ± 1.5, t = 4.6, p bb0.0001). Thirty one percent of boys (n = 48) and 22% of girls (n = 34) reported being high at school after drinking alcohol at least once during the past year. In the total sample, a hierarchical multiple regression analysis was used to evaluate the ability of cannabis use to predict delinquent behaviors after controlling for alcohol misuse and psychopathological variables. In the first step of this analysis, age, sex and cannabis use were entered. Alcohol misuse and psychopathological variables were entered in the second step of the regression. After controlling for alcohol misuse and psychopathological variables cannabis use was no more a significant predictor. Alcohol misuse and psychopathic traits were the only significant predictors of delinquent behaviors. Among cannabis users (n = 97), a hierarchical multiple regression analysis was conducted with the same confounding variables and frequency of cannabis use, as predictor variables. After controlling for alcohol misuse and psychopathological variables frequency of cannabis use remained a significant predictor. Alcohol misuse and psychopathic traits also were significant predictors of delinquent behaviors. The results of these analyses are presented in Table 1. 3. Discussion This study confirms that controlling for confounding variables weakens the associations between cannabis use and delinquent behaviors. After controlling for alcohol misuse, psychopathic and borderline personality traits and depressive symptoms, cannabis use was no more a significant predictor of delinquent behaviors in the total sample. However, among cannabis users, frequency of use remained a significant predictor of delinquency after adjustment for those confounders. These results compared with the findings of previous studies conducted into community samples. McGee et al. (2000) found that after controlling for concurrent conduct disorder cannabis use at age 15 did not predict externalizing behavior at age 18. Fergusson et al. (2002) found that control for confounding factors (adverse life events, deviant peer affiliations, alcohol abuse/dependence) substantially reduced the strength of the association between cannabis use and delinquency. However, at age 14–15years, young people reporting at least weekly cannabis use remained at significantly increased risk of delinquency. Among adolescents aged 12–16years, Monshouwer et al. (2006) found that adjustment for confounders (age, gender, family affluence, household composition and social support, alcohol use and regular smoking) weakened the association between cannabis use and delinquent behavior. However, this association remained significant and was stronger among regular and heavy users. A limitation of our study and of the reviewed studies is that the association found between cannabis use and delinquency after controlling for some confounders may not reflect a causal link between use and delinquency but sources of confounding that have not been taken into account. Another limitation is the reliance on self-report. More studies controlling a larger range of psychosocial and psychopathological confounding factors are needed to explore the association between cannabis use and delinquency among adolescents. However, given the frequency of cannabis use remained a significant predictor of delinquency after adjustment for confounders, our study suggests the interest of taking into account cannabis use in the prevention of delinquent behaviors. References Andershed, H., Kerr, M., Stattin, H., & Levander, S. (2002). Psychopathic traits in nonreferred youths: A new assessment tool. In E. Blaauw & L. Sheridan (Eds.), Psychopaths. Current International Perspectives. (pp. 131−158) Den Haag: Elsevier. Chabrol, H., Ducongé, H., Casas, C., Roura, C., & Carey, K. (2005). Relations between cannabis use and dependence, motives for cannabis use and anxious, depressive and borderline symptomatology. Addictive Behaviors, 30, 829−840. Chabrol, H., Montovany, A., Chouicha, K., Callahan, S., & Mullet, E. (2001). Frequency of borderline personality disorder in a sample of French high school students. Canadian Journal of Psychiatry, 46, 847−849. Choquet, M., Beck, F., Hassler, C., Spilka, S., Morin, D., & Legleye, S. (2004). Les substances psychoactives chez les collégiens et les lycéens: consommation en 2003 et évolutions depuis 10 ans. Tendances, 7, 1−6. Crick, N. R., Murray-Close, D., & Woods, K. (2005). Borderline personality features in childhood: a short-term longitudinal study. Development and Psychopathology, 17, 1051−1070. Fergusson, D. M., Horwood, L. J., & Swain-Campbell, N. (2002). Cannabis use and psychosocial adjustment in adolescence and young adulthood. Addiction, 97, 1123−1135. Frick, P. J., Cornell, A. H., Barry, C. T., Bodin, S. D., & Dane, H. E. (2003). Callous–unemotional traits and conduct problems in the prediction of conduct problem severity, aggression and self-report of delinquency. Journal of Abnormal Child Psychology, 31, 57−470. Howell, D. C. (1997). Statistical methods for psychology. Belmont: Duxbury Press. McGee, R., Williams, S., Poulton, R., & Moffitt, T. (2000). A longitudinal study of cannabis use and mental health from adolescence to early adulthood. Addiction, 95, 491−503. Monshouwer, K., van Dorsselaer, S., Verdumen, J., ter Bogt, T., De Graaf, R., & Volleberg, W. (2006). Cannabis use and mental health in secondary school children: Findings from a Dutch survey. British Journal of Psychiatry, 188, 148−153. Myers, K., & Winters, N. C. (2002). Ten-year review of rating scales. II: Scales for internalizing disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 41, 634−659. Radloff, L. S. (1977). The CES-D scale: A self report depression scale for research in the general population. Applied Psychological Measurement, 1, 385−401. Rey, J. M., Sawyer, M. G., Raphael, B., Patton, G. C., & Lynskey, M. (2002). Mental health of teenagers who use cannabis: Results of an Australian survey. British Journal of Psychiatry, 180, 216−221. Ritakallio, M., Kaltiala-Heino, R., Kivivuori, J., & Rimpelä, M. (2005). Delinquent behaviour and depression in middle adolescence: A Finnish community sample. Journal of Adolescence, 28, 155−159. Schawb-Stone, M., Chen, C., Greenberger, E., Silver, D., Lichtman, J., & Voyce, C. (1999). No safe Haven II: The effects of violence exposure to urban youth. Journal of the American Academy of Child and Adolescent Psychiatry, 38, 359−367. Simons, J., Correia, C. J., Carey, K. B., & Borsari, B. E. (1998). Validating a five-factor motives measure: Relations with use, problems and alcohol motives. Journal of Counselling Psychology, 45, 265−273.
Contents lists available at ScienceDirect
Addictive Behaviors
Cannabis use and delinquent behaviors in high-school students Henri Chabrol ⁎, Carine Saint-Martin Université de Toulouse-Le Mirail, France
a r t i c l e Keywords: Cannabis use Delinquency Psychopathic traits Borderline traits Depressive symptoms Adolescence
i n f o
a b s t r a c t The aim of the study was to evaluate the relative contributions of cannabis use, alcohol use, psychopathic and borderline personality traits, and depressive symptoms in the prediction of delinquent behaviors. Participants were 312 high-school students who completed self-report questionnaires. Hierarchical multiple regression analyses were conducted to investigate the contribution of cannabis use and potential confounding variables to delinquent behaviors in the total sample and in cannabis users. Cannabis use was no more a significant independent predictor of delinquent behaviors after adjustment for alcohol use and psychopathological variables. However, among users, frequency of use remained a significant predictor of delinquency after adjustment for those confounders. © 2008 Elsevier Ltd. All rights reserved.
Cannabis use and delinquency tend to co-occur among adolescents. Delinquent behavior is associated with a multitude of risk factors including psychological, family, peer, and school variables which are also associated with cannabis use. A few crosssectional or longitudinal studies have shown that controlling for confounding risk factors such as family disadvantage or alcohol use weakened or eliminated the association between cannabis use and delinquent behavior (McGee, Williams, Poulton, & Moffitt, 2000; Fergusson, Horwood, & Swain-Campbell, 2002; Monshouwer et al., 2006). However, none of these studies have adjusted for depressive symptoms or personality disorder traits such as psychopathic or borderline traits which are frequent among adolescents and may contribute to both delinquent behaviors and cannabis use (Chabrol, Ducongé, Casas, Roura, & Carey, 2005; Chabrol, Montovany, Chouicha, Callahan, & Mullet, 2001; Frick, Cornell, Barry, Bodin, & Dane, 2003; Rey, Sawyer, Raphael, Patton, & Lynskey, 2002; Rittakalio, Kaltiala-Heino, Kivivuori, & Rimpelä, 2005). The aim of our study was to evaluate the contribution of cannabis use to the prediction of delinquent behaviors after controlling for alcohol use, psychopathic and borderline traits, and depressive symptoms. This is an important topic given the high frequency of cannabis use among adolescents. In France, a nation wide survey showed that 50% of boys and 40% of girls have used cannabis at least once during the past year (Choquet et al., 2004). 1. Methods Data was obtained from students attending two randomly selected high schools in Toulouse, France. Eleven classes were randomly drawn from these high schools. The sample consisted of 312 students (157 girls, 155 boys; mean age = 16.6 ± 1.4; age range = 14–22). Being free of charge, these public high schools were not discriminatory on the basis of income and admitted adolescents with diverse SES levels. This sample, however, is not guaranteed to be representative of the general population of French adolescents. The questionnaires were administered in the classroom by a Master's level psychology student who presented the study and collected the questionnaires. No members of the school staff were present during the administration of the questionnaires. Participants placed completed questionnaires in a sealed envelope. The questionnaires were anonymous, and therefore students were assured that their responses were confidential. Students were informed that participation was voluntary and signed a consent form. No compensation was offered. No student declined to participate in the study. ⁎ Corresponding author. 21 rue des Cèdres, 31400 Toulouse, France. Tel.: +33 561 22 52 90; fax: +33 561 50 39 92. E-mail address: [email protected] (H. Chabrol). 0306-4603/$ – see front matter © 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.addbeh.2008.10.005
188
H. Chabrol, C. Saint-Martin / Addictive Behaviors 34 (2009) 187–189
Delinquent behaviors, alcohol and cannabis use, and psychopathological variables were assessed with self-report scales that had been devised to be used in community samples. Delinquent behaviors were assessed with the Antisocial Behavior Scales (ABS, Schawb-Stone et al., 1999) which include three subscales assessing behavior problems of different severity: 1) conduct problems assessing relatively mild behavior problems, 2) less severe delinquency assessing non-violent antisocial behavior, 3) severe antisocial behavior exploring relatively serious aggressive and antisocial behavior. The respondents are asked to report on a 5-point scale how many times (ranging from “0 times” to “5 or more times”) they were involved in the described behaviors during the past year. In this study, only the two subscales assessing less severe delinquency and severe antisocial behavior were used. The ABS contain one item on alcohol use and one item on cannabis use. To avoid spurious associations, scores were computed without those items. The eight remaining items provide a total sum score that can range from 0 to 32. In this sample, coefficient alpha for those items was 0.78. Alcohol use was assessed with the item of the ABS exploring being high at school after drinking alcohol. Cannabis use in the past 6months was assessed with the 9-point rating scale used by Simons, Correia, Carey, and Borsari (1998) ranging from 0 (no use) to 8 (more than once a day). This scale allowed defining two variables, frequency of use and cannabis use in which use was dichotomized into ‘no use in the last six months’ and ‘use at least once in the past six months’. Psychopathic traits were assessed using the 50-item Youth Psychopathic traits Inventory which was developed for youth ages 12 and older (YPI; Andershed, Kerr, Stattin, & Levander, 2002). Items are worded to assess psychopathic features indirectly. Psychopathic features are framed as characteristics that should seems neutral or even appealing to those with psychopathic traits (e.g. “I usually feel calm when other people are scared”) in order to reduce social desirability response bias. The YPI was validated with a community sample of adolescents. The YPI showed good internal consistency, test–retest reliability and convergent and predictive validity (Andershed et al., 2002). Borderline personality disorder traits were assessed using the 24-item Borderline Personality Features Scale for Children (BPFS-C; Crick, Murray-Close, & Woods, 2005). This scale assesses the core dimensions of borderline personality disorder, affective instability, identity problems, negative relationships, and self-harm. The BPFS-C showed good internal, construct and discriminant validity (Crick et al., 2005). Depressive symptoms were assessed using the Center for Epidemiological Studies—Depression scale (CES-D; Radloff, 1977). The CES-D has been widely used with adolescents as its brevity, format, internal reliability, and concurrent validity are considered to be attractive (Myers & Winters, 2002). The CES-D is composed of 20 items assessing depressed mood, feelings of worthlessness, feelings of hopelessness, feelings that others are hostile or rejecting, psychomotor retardation, loss of appetite, and sleep disturbance. In this sample, coefficient alphas for these three scales were 0.91, 0.82, and 0.89, respectively. A hierarchical multiple regression analysis was conducted to investigate the contribution of cannabis use and potential confounding variables to delinquent behaviors in the total sample. Among cannabis users, a hierarchical multiple regression analysis was performed to assess the contribution of frequency of use. The participants-to-predictors ratio was adequate for multiple regression analysis as it was greater than the traditional guideline of at least ten participants per predictor (Howell, 1997). The proportion of the variance in delinquent behavior explained by the predictors was reported with the multiple R2. The significance of R2 was evaluated by a F statistic. The unique contribution of each predictor was reported with standardized regression coefficient (β), t statistic and p value. All predictor variables had tolerance values N0.4 excluding multicollinearity. All statistical analyses were performed using STATISTICA, Version 8. 2. Results In the total sample, 55% of boys (n = 85) and 24% of girls (n = 37) reported at least one delinquent behaviors during the past year (p b0.0001). Boys reported a greater number of delinquent behavior than girls (2.7 ± 4.2 vs 0.77 ± 2.3, t = 5.1, p bb0.0001). Thirty five
Table 1 Hierarchical multiple regression analyses predicting delinquent behaviors Total sample (N = 312) 2
F
R
Step 1 Sex Age Cannabis use (in the total sample) or Frequency of use (among cannabis users)
13.1 ⁎
0.11
Step 2 Sex Age Cannabis use (in the total sample) or Frequency of use (among cannabis users) Alcohol misuse Psychopathic traits Borderline traits Depressive symptoms
14.6 ⁎
⁎ p b 0.001.
β
Cannabis users (n = 97) t
p
−0.11 0.05 0.18
−1.87 0.88 3.36
0.06 0.38 0.0001
−0.10 0.03 0.04
−1.77 0.61 0.76
0.08 0.54 0.45
0.19 0.35 0.01 −0.06
3.51 5.52 0.20 −1.00
0.001 b0.0001 0.84 0.32
F
R
5.4 ⁎
0.15
5.1 ⁎
0.25
2
β
t
p
− 0.20 − 0.11 0.28
− 1.86 − 1.04 2.50
0.07 0.30 0.01
− 0.03 − 0.11 0.23
− 0.28 − 1.12 2.06
0.78 0.27 0.04
0.22 0.38 − 0.15 0.003
2.28 3.43 − 1.04 0.02
0.02 0.001 0.30 0.98
0.29
H. Chabrol, C. Saint-Martin / Addictive Behaviors 34 (2009) 187–189
189
percent of boys (n = 54) and 27% of girls (n = 43) reported having used cannabis at least once during the last 6months (p = 0.13). Among cannabis users, boys reported a greater frequency of use than girls on Simons et al.'s rating scale: average use for boys was once or twice per week whereas average use for girls was once a month (4.2 ± 2.7 vs 2.1 ± 1.5, t = 4.6, p bb0.0001). Thirty one percent of boys (n = 48) and 22% of girls (n = 34) reported being high at school after drinking alcohol at least once during the past year. In the total sample, a hierarchical multiple regression analysis was used to evaluate the ability of cannabis use to predict delinquent behaviors after controlling for alcohol misuse and psychopathological variables. In the first step of this analysis, age, sex and cannabis use were entered. Alcohol misuse and psychopathological variables were entered in the second step of the regression. After controlling for alcohol misuse and psychopathological variables cannabis use was no more a significant predictor. Alcohol misuse and psychopathic traits were the only significant predictors of delinquent behaviors. Among cannabis users (n = 97), a hierarchical multiple regression analysis was conducted with the same confounding variables and frequency of cannabis use, as predictor variables. After controlling for alcohol misuse and psychopathological variables frequency of cannabis use remained a significant predictor. Alcohol misuse and psychopathic traits also were significant predictors of delinquent behaviors. The results of these analyses are presented in Table 1. 3. Discussion This study confirms that controlling for confounding variables weakens the associations between cannabis use and delinquent behaviors. After controlling for alcohol misuse, psychopathic and borderline personality traits and depressive symptoms, cannabis use was no more a significant predictor of delinquent behaviors in the total sample. However, among cannabis users, frequency of use remained a significant predictor of delinquency after adjustment for those confounders. These results compared with the findings of previous studies conducted into community samples. McGee et al. (2000) found that after controlling for concurrent conduct disorder cannabis use at age 15 did not predict externalizing behavior at age 18. Fergusson et al. (2002) found that control for confounding factors (adverse life events, deviant peer affiliations, alcohol abuse/dependence) substantially reduced the strength of the association between cannabis use and delinquency. However, at age 14–15years, young people reporting at least weekly cannabis use remained at significantly increased risk of delinquency. Among adolescents aged 12–16years, Monshouwer et al. (2006) found that adjustment for confounders (age, gender, family affluence, household composition and social support, alcohol use and regular smoking) weakened the association between cannabis use and delinquent behavior. However, this association remained significant and was stronger among regular and heavy users. A limitation of our study and of the reviewed studies is that the association found between cannabis use and delinquency after controlling for some confounders may not reflect a causal link between use and delinquency but sources of confounding that have not been taken into account. Another limitation is the reliance on self-report. More studies controlling a larger range of psychosocial and psychopathological confounding factors are needed to explore the association between cannabis use and delinquency among adolescents. However, given the frequency of cannabis use remained a significant predictor of delinquency after adjustment for confounders, our study suggests the interest of taking into account cannabis use in the prevention of delinquent behaviors. References Andershed, H., Kerr, M., Stattin, H., & Levander, S. (2002). Psychopathic traits in nonreferred youths: A new assessment tool. In E. Blaauw & L. Sheridan (Eds.), Psychopaths. Current International Perspectives. (pp. 131−158) Den Haag: Elsevier. Chabrol, H., Ducongé, H., Casas, C., Roura, C., & Carey, K. (2005). Relations between cannabis use and dependence, motives for cannabis use and anxious, depressive and borderline symptomatology. Addictive Behaviors, 30, 829−840. Chabrol, H., Montovany, A., Chouicha, K., Callahan, S., & Mullet, E. (2001). Frequency of borderline personality disorder in a sample of French high school students. Canadian Journal of Psychiatry, 46, 847−849. Choquet, M., Beck, F., Hassler, C., Spilka, S., Morin, D., & Legleye, S. (2004). Les substances psychoactives chez les collégiens et les lycéens: consommation en 2003 et évolutions depuis 10 ans. Tendances, 7, 1−6. Crick, N. R., Murray-Close, D., & Woods, K. (2005). Borderline personality features in childhood: a short-term longitudinal study. Development and Psychopathology, 17, 1051−1070. Fergusson, D. M., Horwood, L. J., & Swain-Campbell, N. (2002). Cannabis use and psychosocial adjustment in adolescence and young adulthood. Addiction, 97, 1123−1135. Frick, P. J., Cornell, A. H., Barry, C. T., Bodin, S. D., & Dane, H. E. (2003). Callous–unemotional traits and conduct problems in the prediction of conduct problem severity, aggression and self-report of delinquency. Journal of Abnormal Child Psychology, 31, 57−470. Howell, D. C. (1997). Statistical methods for psychology. Belmont: Duxbury Press. McGee, R., Williams, S., Poulton, R., & Moffitt, T. (2000). A longitudinal study of cannabis use and mental health from adolescence to early adulthood. Addiction, 95, 491−503. Monshouwer, K., van Dorsselaer, S., Verdumen, J., ter Bogt, T., De Graaf, R., & Volleberg, W. (2006). Cannabis use and mental health in secondary school children: Findings from a Dutch survey. British Journal of Psychiatry, 188, 148−153. Myers, K., & Winters, N. C. (2002). Ten-year review of rating scales. II: Scales for internalizing disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 41, 634−659. Radloff, L. S. (1977). The CES-D scale: A self report depression scale for research in the general population. Applied Psychological Measurement, 1, 385−401. Rey, J. M., Sawyer, M. G., Raphael, B., Patton, G. C., & Lynskey, M. (2002). Mental health of teenagers who use cannabis: Results of an Australian survey. British Journal of Psychiatry, 180, 216−221. Ritakallio, M., Kaltiala-Heino, R., Kivivuori, J., & Rimpelä, M. (2005). Delinquent behaviour and depression in middle adolescence: A Finnish community sample. Journal of Adolescence, 28, 155−159. Schawb-Stone, M., Chen, C., Greenberger, E., Silver, D., Lichtman, J., & Voyce, C. (1999). No safe Haven II: The effects of violence exposure to urban youth. Journal of the American Academy of Child and Adolescent Psychiatry, 38, 359−367. Simons, J., Correia, C. J., Carey, K. B., & Borsari, B. E. (1998). Validating a five-factor motives measure: Relations with use, problems and alcohol motives. Journal of Counselling Psychology, 45, 265−273.