RESUMEN
While for decades, temporal stability has been conceived as a defining feature of personality disorders (PDs), cumulative findings appear to question the stability of PDs and PD symptoms over time. However, stability itself is a complex notion and findings are highly heterogenous. Building upon a literature search from a systematic review and meta-analysis, this narrative review aims to capture key findings in order to provide critical implications, both for clinical practice and future research. Taken together, this narrative review revealed that unlike previous assumptions, stability estimates in adolescence are comparable to stability estimates in adulthood and PDs and PD symptoms are not that stable. The extent of stability itself depends yet on various conceptual, methodological, environmental, and genetic factors. While findings were thus highly heterogenous, they all seem to converge in a notable trend towards symptomatic remission, except for high-risk-samples. This challenges the current understanding of PDs in terms of disorders and symptoms and argues instead in favor of the AMPD and ICD-11 reintroducing the idea of self and interpersonal functioning as the core feature of PDs.
RESUMEN
The aim of this systematic review and meta-analysis was to investigate the diagnostic, the dimensional mean-level, and rank-order stability of personality disorders (PDs) and PD criteria over time. EMBASE, PsycInfo, PubMed, and Web of Science were searched for peer-reviewed studies published in either English, German, or French between the first publication of the third edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-III) in 1980 and December 20, 2022. Inclusion criteria were a prospective longitudinal study design, assessing the stability of PDs or PD criteria over at least two measurement occasions at least one month apart, and using the same assessment at baseline and follow-up. Effect sizes included proportion of enduring cases (i.e., diagnostic stability), test-retest correlations (i.e., dimensional rank-order stability), and within-group standardized mean differences (i.e., dimensional mean-level stability), based on the first and last available measurement occasion. From an initial pool of 1473 studies, 40 were included in our analyses, covering 38,432 participants. 56.7% maintained the diagnosis of any PD, and 45.2% maintained the diagnosis of borderline PD over time. Findings on the dimensional mean-level stability indicate that most PD criteria significantly decreased from baseline to follow-up, except for antisocial, obsessive-compulsive, and schizoid PD criteria. Findings on the dimensional rank-order stability suggested moderate estimates, except for antisocial PD criteria, which were found to be high. Findings indicated that both PDs and PD criteria were only moderately stable, although between study heterogeneity was high, and stability itself depended on several methodological factors.