Age-Invariance of the ICD-11 Maladaptive Trait Structure and Connections to Personality Pathology.

Abundant critiques of the categorical approach to personality disorders (PD) resulted in the launch of the 11th International Classification of Diseases dimensional (ICD-11) model. This model provides stylistic descriptions of PD expression by trait levels of Negative Affectivity, Detachment, Dissociality, Disinhibition, and Anankastia. Earlier studies on the structure of ICD-11 maladaptive traits with the Personality Inventory for ICD-11 (PiCD), provided support for a four-factor solution, yet age-invariance was not examined. Assessment can be hindered by age-biased PD features. Therefore, the current study demonstrated scalar measurement invariance of the four-factor solution in a sample of 685 younger and 223 older community dwelling adults. Older adults scored significantly lower than younger adults on Negative Affectivity and Dissociality, yet the relations between PiCD trait domains and measures of personality pathology were largely comparable across age groups. These results are promising for accurate measurement of maladaptive traits across the whole adult lifespan.