L'objectif de cet article est d'étudier les relations entre les symptomatologies anxieuse et dépressive, la symptomatologie de la personnalité limite et la consommation et la dépendance au cannabis chez l'adolescent et le jeune adulte ; 212 adolescents et jeunes adultes ont rempli un questionnaire sur la fréquence de consommation, un questionnaire de dépendance dérivé du MINI (Mini International Neuropsychiatric Interview) et des questionnaires mesurant les symptomatologies anxieuse, dépressive et limite, la CES-D (Center for Epidemiological Studies-Depression scale) , la STAI-YA (Échelle d'anxiété-état de Spielberger) et le BPI (Inventaire de personnalité limite). Parmi les 212 sujets, 114 (54 %) étaient des consommateurs (45,3 % des filles, 66,6 % des garçons). Parmi les consommateurs, 36 % des filles avaient une dépendance probable au cannabis contre 64 % des garçons. Les scores du BPI et de la CES-D étaient corrélés significativement à la durée de la consommation. Les analyses de régression prédisant la fréquence de la consommation ont montré que la symptomatologie limite était le seul prédicteur significatif. La dépendance était prédite par la fréquence de la consommation et la symptomatologie limite. Le fait qu'une proportion élevée des sujets soient des consommateurs quotidiens ou pluriquotidiens est un facteur de confusion maintenant inévitable dans les études épidémiologiques du fait de l'augmentation de la fréquence de consommation : une proportion élevée de sujets étaient probablement sous les effets d'une prise lors de la passation des questionnaires, ce qui a pu contribuer à masquer une symptomatologie chronique anxieuse ou dépressive. La symptomatologie limite et la symptomatologie dépressive sont liées à la durée de consommation, ce qui suggère que la consommation de cannabis les fait apparaître ou aggrave une symptomatologie limite ou dépressive préexistante. Les analyses de régression montrent principalement une forte liaison entre la symptomatologie limite et la fréquence de consommation et la dépendance au cannabis. Ce résultat peut être lié au fait que les effets aigus et chroniques du cannabis se combinent pour exacerber la symptomatologie limite, alors que les effets aigus et chroniques du cannabis sur l'humeur qui peuvent être inverses obscurcissent les relations entre symptomatologie anxieuse et dépressive et cannabis. La symptomatologie limite paraît fortement liée à la consommation et à la dépendance au cannabis. La personnalité limite n'est pas le seul facteur de risque de la consommation. Les traits de personnalité limite même à un niveau subclinique représentent probablement un facteur de risque qui apparaît plus important que l'intensité de la symptomatologie anxieuse et dépressive qui peut être masquée par l'effet aigu du produit. La fréquence des consommateurs quotidiens ou quasi quotidiens chez les adolescents et chez les adultes jeunes est probablement un facteur de confusion important dans l'étude des relations entre troubles anxieux et dépressifs et consommation de cannabis.

The aims of this paper is to study the relations between anxious, depressive and borderline symptomatology and cannabis use and dependence in adolescents and young adults. A convenient sample of 212 subjects composed of high-school and college students from Toulouse, France (85 boys, 127 girls ; mean age = 18.3 ± 1.8 years) completed questionnaires assessing the patterns of cannabis use, age of first use, the symptoms of dependence using a questionnaire derived from the Mini International Neuropsychiatric Interview, and the anxious, depressive and borderline symptomatology using the STAI-YA (State-Trait Anxiety Inventory ; Spielberger et al. , 1970), the CES-D (Center for Epidemiological Studies-Depression scale ; Radloff, 1977) and the BPI (Borderline Personality Inventory ; Leichsenring, 1999), respectively ; 54 % of subjects reported having used cannabis once during the last 6 months (45.3 % of girls and 66.6 % of boys, p = 0.002). Frequency of use was higher in boys : eg , 61 % of boys used cannabis at least almost daily versus 31 % of girls (p < 0.00001). Age of first use was lower in boys than in girls (14.6 ± 2.6 versus 15.7 ± 2.3, t = - 2.46, p = 0.02). Length of use was higher in boys than in girls (3.9 ± 2.2 versus 3 ± 1.6, t = 2.2, p = 0.03). Among users, near of 64 % of boys and 36 % of girls met the criteria for cannabis dependence (p = 0.003). BPI, CES-D and STAI-YA scores were compared between non-users and users and between non-dependent and dependent users : the only significant differences were that BPI scores were higher in users versus non-users and in dependent users versus non-dependent users ; CES-D and STAI-YA scores did not distinguished users from non-users and dependent users from non-dependent users. BPI and CES-D scores were correlated with the length of cannabis use (Pearson r = 0.19 and r = 0.19, respectively, p < 0.05). In a multiple regression analysis predicting the frequency of cannabis use, we entered age, sex, CES-D, STAI-YA and BPI scores. This model accounted for 23 % of the variance of the frequency of use (F _5,206 = 14.4, p < 0.0001). Sex, age, and BPI scores were significant predictors (β = - 0.31, t = - 5.03, p < 0.0001 ; β = 0.29, t = 4.87, p < 0.0001, β = 0.27, t = 3.80, p < 0.0001, respectively). CES-D scores were a nearly significant predictor (β = - 0.17, t = - 1.96, p = 0.051). STAI-YA scores were not a significant predictor (β = 0.11, t = 1.29, p = 0.20). In a multiple regression analysis predicting the dependence scores, we entered age, sex, frequency of use, CES-D, STAI-YA and BPI scores. This model accounted for 41 % of the variance of the dependence score (F _6,107 = 12.6, p = 0.005). Frequency of use and BPI scores were significant predictors (β = 0.51, t = 6.12, p < 0.0001 ; β = 0.26, t = 2.86, p = 0.005, respectively). Age, sex, CES-D and STAI-YA scores were not significant predictors (β = - 1.04, t = - 1.32, p = 0.19 ; β = 0.008, t = 0.09, p = 0.92 ; β = 0.16, t = 1.53, p = 0.12 ; β = - 0.14, t = - 1.46, p = 0.15, respectively). The frequency of use and dependence observed in this study confirm the results obtained in epidemiological studies of use and dependence in France. The high frequency of daily or almost daily users suggests that a high proportion of subjects were « high » while completing the questionnaires. This is a confounding variable now inevitable in epidemiological studies of cannabis use given the high proportion of daily users. The consequence may be that responses to mood questionnaire express both the acute effect of cannabis consumption and the chronic effect that might be different : the acute euphoriant effect of cannabis may mask a chronic depressive symptomatology induced by chronic cannabis consumption. The antidepressant and anti-anxiety acute effect of cannabis may explain that CES-D and STAI-YA scores did not distinguished users from non-users and dependent users from non-dependent users. The correlation between length of use and CES-D scores may reveal the depressant chronic effect of long-term use. The correlation between length of use and BPI scores suggest that long-term cannabis use induces an increase in borderline symptomatology. Results of the regression analyses suggest that the borderline symptomatology is highly linked to frequency of use and cannabis dependence. This may be due to the increase in borderline symptomatology induced by both acute and chronic effects of cannabis. The relation between cannabis use and dependence on one hand and anxious and depressive symptomatology on the other hand may have been obscured by the acute mood effect of cannabis consumption. Borderline symptomatology appeared to be highly linked to cannabis use and dependence in adolescents and young adults. Borderline personality disorder in adolescents is not the only risk factor for cannabis use and dependence in adolescents : borderline symptomatology even at a subclinical level seems to be a higher risk factor than anxious or depressive symptomatology. The frequency of daily or almost daily users may be a confounding variable for the study of relations between anxiety and depressive disorders in adolescents and young adults.