Psychiatric comorbidity in hospitalized adolescents with borderline personality disorder.

OBJECTIVE

The goal of this study was to carry out the first comprehensive assessment of psychiatric comorbidity in adolescents (aged 12-17 years) with DSM-IV criteria for borderline personality disorder (BPD) compared to a psychiatric comparison group without BPD. Complex comorbidity (a hallmark feature of adult BPD and defined as having any mood or anxiety disorder plus a disorder of impulsivity) was also examined as a distinguishing feature of adolescent BPD.

METHOD

Consecutively admitted patients (October 2008 to October 2012) to an inpatient psychiatric hospital received parental consent and gave assent for participation in the study (N = 418), with the final sample after exclusions consisting of 335 adolescent inpatients. A comprehensive, multimethod approach to determining psychiatric comorbidity was used, including both an interview-based (categorical) and a questionnaire-based (dimensional) assessment as well as both parent and adolescent self-report. Measures included the Diagnostic Interview Schedule for Children (NIMH-DISC-IV), Child Behavior Checklist (CBCL), Youth Self-Report (YSR), Car, Relax Alone, Forget, Friends, Trouble (CRAFFT), and the Childhood Interview for DSM-IV Borderline Personality Disorder (CI-BPD).

RESULTS

Thirty-three percent of the final sample met criteria for BPD. Adolescent inpatients with BPD showed significantly higher rates of psychiatric comorbidity compared to non-BPD psychiatric subjects for both internalizing (χ²₁ = 27.40, P < .001) and externalizing (χ²₁ = 19.02, P < .001) diagnosis. Similarly, using dimensional scores for self-reported symptoms, adolescent inpatients with BPD had significantly higher rates of psychiatric comorbidity compared to non-BPD subjects for internalizing (t₃₂₉ = -6.63, P < .001) and externalizing (t₃₂₉ = -7.14, P < .001) problems. Parent-reported symptoms were significantly higher in the BPD group only when using a dimensional approach (internalizing: t₃₂₁ = -3.42, P < .001; externalizing: t₃₂₁ = -3.32, P < .001). Furthermore, significantly higher rates of complex comorbidity were found for adolescents with BPD (χ²₁ = 26.60, P < .001). Moreover, externalizing and internalizing problems interacted in association with borderline traits (B = .25; P < .001).

CONCLUSIONS

Similar to findings in adult studies of BPD, adolescents with BPD demonstrate significantly more complex comorbidity compared to psychiatric subjects without BPD.