Prevalence and comorbidity of borderline personality traits in the Quebec general population aged 12-14 years

The early identification of borderline personality traits (BPT) in adolescents helps to prevent their progression. Data are available for the clinical population, but little has been published on the general population, especially regarding age and sex distribution in adolescence. Even less is known about the comorbidity of BPT with other mental disorders.

We estimated the prevalence of BPT, by sex, age, and comorbidity, in a sample of adolescents aged 12-14 years (n = 799) from the Quebec Mental Health Survey. A complex sampling design was used to ensure representativeness. BPT was assessed with the abbreviated-diagnostic interview for borderlines-revised, with the adolescent as an informant. Reliability coefficients were above 0.80. Several levels of severity were explored using an independent criterion, defined by impairment according to the Columbia impairment scale.

The overall prevalence of BPT was 6.3%. Prevalence estimates for the most impaired were 3.2% for the entire sample and 1.3% for 12-year-olds. Prevalence increased significantly with age for most impairment levels but did not differ significantly between the sexes. In adolescents, BPT displayed moderate-to-strong comorbidity with anxiety (AD) and insomnia disorders, and very strong comorbidity with depressive (DD), attention deficit hyperactivity (ADHD), and oppositional defiant/conduct disorders (ODD/CD).

We, therefore, make two clinical recommendations for child psychiatry practice: (1) with respect to the lower rate of male adolescents attending BPT Health Programs, increase BPT screening in male adolescents; (2) evaluate BPT when children with ADHD or ODD/CD develop AD or DD during adolescence.