The Role of Personality Functioning on Early Drop out in Outpatient Substance Misuse Treatment

Background: Early drop out is a major factor contributing to positive outcomes, but the supporting literature remains limited. It is difficult to draw conclusions regarding predictors of dropout, and there is a need to target clients' major early attrition vulnerabilities. Despite empirically validated models for assessing personality, little is known about its role in the treatment process. Studies that have been conducted in this area have focused mainly on stable personality traits and provide conflicting evidence. Aims: The aim of this study is to examine to what extent service users' personality functioning are potential determinants of early drop out. Methodology: A cross-sectional multi-site design examined the therapy process in a naturalistic setting in 5 outpatient preparation treatment centers with 210 service users. The current study adopts a contemporary dimensional-based framework, similar to the Alternative Model of Personality Disorder of the DSM-V and examines the role of characteristic adaptations (SIPP-118) on early drop out (CEST-Intake). Findings: From the broad spectrum of personality traits, only Depression remained significant predictor of drop out. Higher dysfunctional levels in Social Concordance [OR] = 1.85, Wald =19.87, p =.002, 95% CI [1.1, 1.9] as well as the facets Aggression Regulation, Respect and Purposefulness were also predictors of early drop out, while Treatment Readiness and Desire for Help accounted for a significant amount of variance. Conclusions: These findings extend our knowledge of the predictive role of characteristic adaptations in treatment and suggest it may be important to assess these individual differences early on and to design personalized-informed interventions.