Levels of Personality Functioning Questionnaire 12-18 (LoPF-Q 12-18): Factor Structure, Validity, and Clinical Cut-Offs

Abstract

The Levels of Personality Functioning Questionnaire 12-18 (LoPF-Q 12-18) is the only self-report measure informed by the Level of Personality Functioning ( Diagnostic and Statistical Manual of Mental Disorders [5th ed.; DSM-5; American Psychiatric Association, 2013]) Alternative Model of Personality Disorders developed for adolescents. The present investigation includes two studies evaluating the English LoPF-Q 12-18. In Study 1, single-factor and bifactor structures (unidimensional severity criterion and four specific factors: identity, self-direction, empathy, intimacy) were evaluated in an ethnically diverse community sample ( N = 453; age 10–18; 57% female). Study 2 used a community control ( n = 298; age 10–18; 54.4% female) and clinical sample ( n = 94; age 11–18; 58.5% female) to examine reliability, validity, and clinical utility. Study 1 results supported the bifactor model, with a robust general factor and little multidimensionality caused by the group factors, suggesting an essentially unidimensional structure. Study 2 revealed good internal consistency and construct validity and provided clinical cut-offs, supporting the use of the LoPF-Q 12-18 total score in research and clinical applications.

Personality pathology in adolescence: relationship quality with parents and peers as predictors of the level of personality functioning

“…The LoPF-Q 12-18 scores differentiate adolescents with 5 or more BPD symptoms from the school-based sample of adolescents with BPD (Cohen's d = 1.2), which proved the clinical validity of the LoPF-Q 12-18 (unpublished dataset). Based on the previous discussions about the LoPF-Q structure and existing attempts to identify the most valid structure of the instrument, we have decided to use a total LoPF-Q score as a unidimensional measure of personality functioning [44,45]. In the current study, the internal consistency was excellent for the total scale (α = 0.97).…”

Diagnostic accuracy of severity measures of ICD-11 and DSM-5 personality disorder: clarifying the clinical landscape with the most up-to-date evidence

“…Likewise, the third ( 16 ) and eleventh ( 36 ) studies reported sensitivity and specificity metrics for two or more PD dysfunction thresholds; on the other hand, study 8 ( 34 ) reported other dysfunction thresholds without these metrics. The fourth ( 15 ) and fifth ( 32 ) studies reported the optimal cut-off points and their diagnostic accuracy metrics according to the setting and reference standard, respectively. Only study 10 ( 38 ) reported additional sensitivity and specificity metrics for all cut-off points of the measure used as an index test.…”

Operationalizing intimacy and identity aspects of personality functioning in relation to personality disorder in adolescents

“…For the assessment of AMPD Criterion A, a range of self-report and interview-based measures have been developed. These measures show strong validity and reliability in adults [see (15) and ( 16) for a review] and there is an emerging literature validating Criterion A-related measures in adolescents [e.g., (17)(18)(19)(20)]. The limitations of self-report measures to adequately assess Criterion A function, given the known impairment in self-reflection associated with personality pathology, have been noted (21,22), and the potential of using experimental or more performance-based measures has been suggested-in particular for Criterion A (23).…”