Manifestations of personality impairment severity: comorbidity, course/prognosis, psychosocial dysfunction, and 'borderline' personality features.

•Personality impairment is the core of PD pathology and an essential indicator of PD severity.•Comorbidity, problematic course, and psychosocial dysfunction are indicators of PD severity.•A higher order factor of general PD severity is marked most strongly by borderline PD features.•Borderline PD features may be helpful in defining and assessing personality-impairment severity.