The prognostic utility of personality traits versus past psychiatric diagnoses: Predicting future mental health and functioning

Abstract

Past psychiatric diagnoses are central to patient case formulation and prognosis. Recently, alternative classification models such as the Hierarchical Taxonomy of Psychopathology (HiTOP) proposed to assess traits to predict clinically-relevant outcomes. The current study directly compared personality traits and past diagnoses as predictors of future mental health and functioning in three independent, prospective samples. Regression analyses found that personality traits significantly predicted future first onsets of psychiatric disorders (ΔR²=06-.15), symptom chronicity (ΔR²=.03-.06), and functioning (ΔR²=.02-.07), beyond past and current psychiatric diagnoses. Conversely, past psychiatric diagnoses did not provide an incremental prediction of outcomes when personality traits and other concurrent predictors were already included in the model. Overall, personality traits predicted a variety of outcomes in diverse settings, beyond diagnoses. Past diagnoses were generally not informative about future outcomes when personality was considered. Together, these findings support the added value of personality traits assessment in case formulation, consistent with HiTOP model.

Keywords: Diagnosis; Functioning; Personality traits; Psychopathology.

Figure 1 –. Incremental predictions of mental health outcomes by personality traits and past diagnoses.

Notes: Asterisk denotes significant ΔR² at p<.05 when the predictor was added to the model in the final regression block, after accounting for all other predictors. In the community adolescents sample, the effect size for analyses of first onsets is reported as Nagelkerke pseudo R².