The Alternative Model for Personality Disorders (AMPD) in the Diagnostic and Statistical Manual of Mental Disorders (DSM), fifth edition (DSM-5), defines personality functioning by assessment of impairment in Identity and Self-direction (Self-component) and in Empathy and Intimacy (Interpersonal). These four domains constitute the Level of Personality Functioning Scale (LPFS), a trans-diagnostic measure of PD severity. The association between the LPFS and psychosocial impairment based on other previously established psychosocial functioning instruments has not been reported. A total of 317 individuals, including a representative clinical sample of 282 patients (192 with a PD diagnosis), was evaluated with the Structured Clinical Interview for the DSM-5 AMPD (SCID-5-AMPD) Module I. Self-reported impairment was measured by the Work and Social Adjustment Scale (WSAS) and social and occupational impairment was assessed by the functioning score of Global Assessment of Functioning scale (GAF-F). WSAS and GAF-F both correlated significantly with mean LPFS scores and the sum of DSM-IV PD criteria. For both measures, the mean LPFS was a stronger predictor for psychosocial impairment than the sum of DSM-IV PD criteria. Within the LPFS, the Self component was a better predictor than the Interpersonal component for both WSAS and GAF-F. For the four domains the results diverged, with Identity as the strongest predictor by far for WSAS. Empathy was the only significant predictor for impairment evaluated by GAF-F, but its contribution to variance was not substantial.

The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) presents an alternative model for personality disorders in which severity of personality pathology is evaluated by the Level of Personality Functioning Scale (LPFS). The Structured Interview for the DSM-5 Alternative Model for Personality Disorders, Module I (SCID-5-AMPD I) is a new tool for LPFS assessment, but its interrater reliability (IRR) has not yet been tested. Here we examined the reliability of the Norwegian translation of the SCID-5-AMPD I, applying two different designs: IRR assessment based on ratings of 17 video-recorded SCID-5-AMPD I interviews by five raters; and test-retest IRR based on interviews of 33 patients administered by two different raters within a short interval. For the video-based investigation, intraclass correlation coefficient (ICC) values ranged from .77 to .94 for subdomains, .89 to .95 for domains, and .96 for total LPFS. For the test-retest investigation, ICC ranged from .24 to .72 for subdomains, .59 to .90 for domains, and .75 for total LPFS. The test-retest study revealed questionable reliability estimates for some subdomains. However, overall the level of personality functioning was measured with a sufficient degree of IRR when assessed by the SCID-5-AMPD I.

The Level of Personality Functioning Scale (LPFS) of the Alternative DSM-5 Model for Personality Disorders (AMPD) was formulated to assess the presence and severity of personality disorders (PDs). Moderate impairment (Level 2) in personality functioning, as measured by the LPFS, was incorporated into the AMPD as a diagnostic threshold for PD in Criterion A of the general criteria, as well as for the "any two areas present" rule for assigning a specific PD diagnosis. This study represents the first evaluation of the diagnostic decision rules for Criterion A, in a clinical sample (N = 282). The results indicate that an overall diagnostic threshold for PDs should be used with caution because it may not identify all DSM-IV PDs. The "any two areas present" rule proved to be a reasonable alternative, although this finding should be interpreted with caution because the LPFS does not measure the disorder-specific A criteria.

The current study aims to examine the psychometric properties of the Structured Clinical Interview for the DSM-5 Alternative Model for Personality Disorders Module I (SCID-5-AMPD-I) assessing the Level of Personality Functioning Scale (LPFS) in a heterogeneous sample of 282 nonpsychotic patients. Latent variable models were used to investigate the dimensionality of the LPFS. The results indicate that the LPFS, as assessed by the SCID-5-AMPD-I, can be considered as a unidimensional construct that can be measured reliably across a wide range of the latent trait. Threshold parameters for the 12 indicators of the LPFS increased gradually over the latent scale, indicating that the five LPFS levels were ordered as predicted by the model. In general, the increase of threshold parameters was relatively small for the shift from Level 2 to Level 3. A better distinction among the different severity levels might be obtained by fine-tuning the interview guidelines or the Level 2 indicators themselves.