Impaired Personality Functioning in Children and Adolescents Assessed with the LoPF-Q 6-18 PR in Parent-Report and Convergence with Maladaptive Personality Traits and Personality Structure in School and Clinic Samples

To investigate if the Personality Disorder (PD) severity concept (Criterion A) of ICD-11 and DSM-5 AMPD is applicable to children adolescents, following lifespan perspective mental disorders, age-specific informant-adapted assessment tools are needed. The LoPF-Q 6-18 PR (Levels Functioning Questionnaire Parent Rating) was developed assess Impaired (IPF) in aged 6–18 parent-reported form. It based on established self-report questionnaire 12-18. Psychometric properties were investigated a German-speaking clinical school sample containing 599 subjects. final 36-item version showed good scale reliabilities with 0.96 for total IPF 0.90-0.87 domain scales Identity, Self-direction, Empathy, Intimacy/Attachment an acceptable model fit hierarchical CFA CFI = 0.936, RMSEA 0.078, SRMR 0.068. score discriminated significantly large effect sizes between population (a) adolescent PD patients (d 2.7 standard deviations) (b) younger (6–11-year-olds) internalizing externalizing disorders 2.2 deviations). Informant agreement parent at 0.47. Good construct validity can be assumed given sound covariation related measures psychopathology (CBCL 4-18, STiP-5.1, OPD-CA2-SQ PR) maladaptive traits (PID5BF+ M CA IRF) line theory matching result patterns obtained older samples self-report. results suggest that assessments equivalent self-reported Criterion A B. Assessing as early age six might valuable step foster detection PD, or personality development, respectively individuals risk.