Categorical Stability of a Personality Disorder From Adolescence to Young Adulthood and Risk Factors for a Personality Disorder in Adulthood in a High-Risk Sample

Theoretical background: Against the current assumption that personality disorders (PDs) are "enduring," "pervasive," "inflexible," and "stable" over time, studies from the past decade show that the stability of PDs is not much higher than the stability of other mental disorders, and that PD can be treated, especially if detected before the age of 18 years. Objective: The current paper investigates the prevalence and the categorical mean-level stability of PDs from adolescence to young adulthood in a high-risk sample. In addition, this study identifies possible risk factors among adolescents for a PD in later adulthood. Method: In total. the current analyses included 180 young adults (mean age: 26.3 years; 32.2% women) with a history of child welfare and juvenile justice placements, taking part in a large-scale longitudinal cohort study in Switzerland. PDs were assessed with the Structured Clinical Interview for DSM-4 Axis II disorders (SCID-II) at baseline (t0) and at a 10-year follow-up (t1). Results: The sociodemographic description of the sample revealed that participants with a PD were significantly more likely to be placed by the legal system and more likely to change child welfare placements during out-of-home care than participants without a PD. In addition, participants with PD had lower educational backgrounds and were more likely to receive financial assistance through disability benefits. Overall, 64 (35%) participants met the criteria for a PD diagnosis at follow-up, while almost half thereof (16.7%) met more than one PD diagnoses. Regarding individual PD diagnoses, antisocial PD and borderline PD were the most frequent diagnoses, with a prevalence of 20.0% (n = 36) and 9.4% (n = 17) respectively. A total of 13.8% (n = 19) of the participants met a PD only at baseline, and 18.8% (n = 26) of the participants met a PD only at follow-up. More than half of the participants (56.9%) did not meet a PD diagnosis, neither at baseline nor at follow-up. A total of 12.3% (n = 17) met a PD diagnosis at both baseline and follow-up, resulting in a mean-level categorical stability of 47.2 %. A previous PD diagnosis, psychopathic personality traits, substance abuse, emotional neglect, cumulated maltreatment experiences, and offense severity during adolescence were found to be significant risk factors for a PD in adulthood. Discussion and conclusion: Taken together, adults with a history of child welfare and juvenile justice placements present a highly burdened sample, especially when suffering from a PD. The categorical mean-level stability of any PD can be classified only as moderate in this high-risk sample, which emphasizes the need to overcome the assumption of equating PDs with a lifelong, unchangeable outcome. This, in turn, underlines the importance of early detection and treatment of PDs, by identifying possible risk factors to ensure individualized, tailor-made treatments and thus prevent potential symptom chronicity.