This psychometric validation study evaluated the Turkish version of the Levels of Personality Functioning Questionnaire Adult (LoPF-Q Adult) in 348 Turkish adults, including 283 community participants and 65 clinical participants (34 diagnosed with personality disorders). The study compared the community sample against the clinical sample to assess the questionnaire's reliability, validity, factor structure, and discriminative ability.
The LoPF-Q Adult demonstrated excellent internal consistency with a Cronbach's alpha of .96. It showed strong positive correlations with general psychopathology measures (BSI) for convergent validity. Personality disorder patients scored significantly higher than community participants with a large effect size (d=1.56). Bifactor modeling revealed a dominant general factor capturing most shared variance, and ROC analysis showed good discriminative ability with an area under the curve of .85.
No safety or tolerability data were reported. Key limitations include the preliminary nature of findings pending longitudinal and invariance studies, and cross-age structural compatibility should not be interpreted as direct evidence of developmental continuity. The study supports the reliability and clinical utility of the Turkish LoPF-Q Adult as a dimensional measure of personality functioning severity, but clinicians should await further validation before definitive implementation.
How do you accurately measure the depth of someone's personality struggles? A new study tested a Turkish version of a questionnaire designed to do just that. Researchers found the tool was highly consistent in its measurements and strongly correlated with general psychological distress. Most importantly, it clearly distinguished between a group of 34 adults diagnosed with personality disorders and a larger community sample, with the clinical group scoring significantly higher.
The study involved 348 Turkish adults, including both community members and clinical patients. The questionnaire's structure suggested it was measuring one core dimension of personality functioning, and its ability to discriminate between groups was good. This is a validation study, meaning it's checking if the tool works as intended, not testing a treatment.
While these results are encouraging for clinicians in Turkey looking for reliable assessment tools, the authors are clear about the limits. The findings are preliminary. They need to be confirmed with longer-term studies and research across different age groups. The compatibility of the tool's structure with a version for adolescents is consistent, but it's not yet proof of how personality functioning develops over time.
What this means for you: A new Turkish questionnaire reliably identifies personality struggles, but findings are early.
View Original Abstract ↓
IntroductionThe Levels of Personality Functioning Questionnaire (LoPF-Q) is a self-report tool developed to assess impairments in personality functioning, informed by Criterion A of the DSM-5 Alternative Model for Personality Disorders (AMPD) and the ICD-11 dimensional framework. The LoPF-Q 12–18 represents the adolescent version of the LoPF-Q Adult and has demonstrated robust psychometric properties in Turkish adolescent samples; however, the psychometric performance of the adult version in Turkish populations and its structural comparability across age groups remain underexplored.MethodsThe current study evaluated the reliability, validity, and structural characteristics of the Turkish LoPF-Q Adult in a combined sample of 283 community adults and 65 clinical participants. Internal consistency was assessed via Cronbach’s alpha. Convergent and discriminant validity were examined through associations with the Brief Symptom Inventory (BSI). Clinical validity was evaluated by comparing LoPF-Q scores between the community group and a subset of patients diagnosed with personality disorders (n = 34). Additionally, bifactor modeling and receiver operating characteristic (ROC) analyses were conducted to examine factor structure and discriminative ability.ResultsThe LoPF-Q Adult demonstrated excellent internal consistency (Cronbach’s α =96). Strong correlations with general psychopathology on the BSI supported convergent validity, with distinct subscale-level patterns consistent with theoretical expectations. Clinical comparisons revealed significantly higher LoPF-Q total scores in individuals with personality disorders than in the community sample, with a large effect size (d = 1.56). Bifactor indices indicated a dominant general factor capturing the majority of shared variance, aligning with prior adolescent validation studies. ROC analysis yielded an area under the curve of.85, with an optimal cut-off score that provided balanced sensitivity and specificity.DiscussionThese findings support the reliability and clinical utility of the Turkish LoPF-Q Adult as a dimensional measure of personality functioning severity. The strong general factor, robust discrimination between clinical and non-clinical groups indicates that the instrument captures structural impairment central to contemporary AMPD and ICD-11 models. Together with prior adolescent findings, the results are consistent with cross-age structural compatibility in the assessment of personality functioning rather than direct evidence of developmental continuity, while remaining preliminary pending longitudinal and invariance studies.
