Why should you pay attention to personality pathology in geriatric psychiatry? To what extent is mental well-being determined by this? How does that relate to the influence of mental disorders? Does the Alternative Dimensional Model of Personality pathology (AMPD) as proposed by the DSM-5 provide more insight into this than the DSM-IV and DSM-5 categorical diagnoses of personality disorders?

These questions were examined in baseline data of 145 patients included in our randomized controlled trial (RCT) into group Schema therapy enriched with psychomotor therapy in older patients with a personality disorder (see Oude Voshaar in this symposium). Mental well-being was measured by a combination of psychological distress (53-item Brief Symptom Inventory), positive mental health (Warwick-Edinburgh Mental Well-being Scale), assessment of own health (RAND-36), and satisfaction with life (Cantrill’s ladder). Personality pathology was assessed according to the categorical personality model using the Structured Clincal Interview for Personality Disorder (SCID-II) as well as the AMDP DSM-5 model using the Severity Indices of Personality Problems (SIPP-short form) and the Personality Iventory for DSM-5 (PID-25). The relationship between personality pathology and mental well-being was investigated using multivariate regression analysis.

Three quarters of the included people with a personality disorder also had another psychiatric disorder (beyond personality pathology). However, personality pathology was found to be responsible for the bulk of the mental health burden and outweighed the influence of these psychiatric disorders. Personality dimensions were highly predictive of mental well-being. This contrasted with the absence of any influence from categorical personality disorders. Although dimensions of personality functioning – and in particular Identity Integration – were the primary predictors of mental well-being, pathological traits added significant predictive value (particularly Disinhibition and Negative Affectivity).

Personality pathology seriously affects the mental well-being of patients and exceeds the impact of comorbid psychiatric disorders. Contrary to the assumption in the alternative DSM-5 and ICD-10 model, both personality functioning and pathological traits contribute to this impact on mental well-being. Screening and systematic assessment of personality pathology in geriatric psychiatry seems warranted.