Comparaison d'Une thérapie basée Sur la Mentalisation et d'un Traitement inspiré de la thérapie Comportementale Dialectique Sur l'Utilisation Des Services et Sur le Taux d'Abandon Dans Une Population Clinique Adulte Atteinte d'un Trouble de la personnalité du Groupe B

Cluster B personality disorders (borderline, narcissistic, antisocial and/or histrionic) are an important clinical consideration because of their high prevalence and associated morbidity. Although many studies examine borderline personality disorder, few of them explore cluster B personality disorders as a whole. In clinical practice, personality disorders are frequently comorbid. Patients who receive services in specialized clinics for these disorders often have a complex diagnosis that include many cluster B personality disorders. Therefore, our study globally examines patients with cluster B personality disorders even though borderline personality disorder is empirically the most studied psychopathology. Previous data suggests that borderline personality disorder has a prevalence of 2% in the general population, of 25% in the clinical psychiatric population and of 15% in all visits to the emergency room. Furthermore, it is associated with social costs estimated from 15,000$ to 50,000$ USD per patient per year. In Quebec, this psychopathology is associated with an increased mortality rate compared to the general population, totaling a loss of nine years for women and 13 years for men of life expectancy. Other studies suggest that borderline personality disorder is often comorbid with other personality disorders, including those in cluster B. The population with comorbid personality disorders have a worse prognosis and a lower chance of reaching symptomatic remission, which is the reason why it is crucial to better understand and study patients with cluster B personality disorders.

The study compares the effectiveness of two psychotherapies for borderline personality disorder, mentalization-based therapy and a modified version of Linehan's dialectical behavior therapy, in a retrospective naturalistic study of patients with at least one cluster B personality disorder who have undergone either treatment. The scarcity of data on cluster B personality disorders and on the comparison between MBT and DBT further highlights the necessity of a naturalistic study like ours to examine both aspects and bring research closer to the clinical setting. Based on clinical observations, the investigators believe that there will be no statistically significant difference between either treatment.