Examining the Validity of the Levels of Personality Functioning Questionnaire for Adolescents Aged 12-18 (LOPF-Q 12-18): A Replication and Extension With a Sample of Lithuanian Adolescents.

With the shift to the dimensional model of personality pathology, the need for measures assessing personality functioning in adolescence has emerged. The Levels of Personality Functioning Questionnaire 12-18 (LoPF-Q 12-18) was developed specifically for adolescents, tailoring the Alternative Model of Personality Disorders in the DSM-5. Using the Lithuanian LoPF-Q 1218, we further investigate its validity by reexamining its factorial structure and extending convergent, discriminant, and incremental validity analyses. A total of 1,048 community-based and clinically referred 12-18-year-old adolescents completed the LoPF-Q 12-18 along with other self-report measures of personality pathology, psychopathological symptoms, and psychosocial functioning. In line with previous findings, the results supported the bifactor model consisting of a strong general factor and little multidimensionality caused by the group factors, overall suggesting an essentially unidimensional structure. Further analyses provided additional information on the construct validity of the LoPF-Q 12-18.