The Interplay of Personality Functioning and Affect-Event Dynamics in Predicting Future Impairment and Depression – A Large Mobile Mental Health Ambulatory Assessment Study

Since the introduction of the dimensional assessment of personality functioning (PF) in DSM-5 and ICD-11, impairments in PF have consistently been related to transdiagnostic risk-factors for mental health. However, ecological momentary assessment (EMA) investigating PF in relation to affect-event dynamics and other psychopathology are scarce. Leveraging EMA data from 16,038 mental health app users, this study examines how baseline impairments in PF, within-person affect-event dynamics, and depression predict longitudinal outcomes in PF impairment and depression severity. We hypothesized a central role of PF in these relationships. Within the first month of usage, on average, 69.3 (range 31-142) mood assessments and 63.3 (range 25 - 133) event assessments were available per user. Dynamic structural equation models (DSEM) showed that baseline depression was associated with weakened or even negative concurrent and cross-lagged links between mood and positive events, including lower inertia and reduced likelihood of positive events. In contrast, baseline PF impairment was associated with persistence, emotional impact and volatility of interpersonal conflict events as well as with greater mood instability. Over a one-year follow-up (N = 1,464; M = 1,236 assessments per user), DSEM identified different patterns: Future PF impairment and depression were both predicted by less concurrent mood-positive event associations, less positive event volatility, and baseline average mood/events. Among affect-event dynamics, cross-lagged effects of interpersonal conflicts on mood explained the highest unique variance of future PF impairment (ΔR2 5.9%). Notably, baseline PF exhibited the strongest overall predictive utility (ΔR2 = 19.5%), followed by baseline depression symptoms (ΔR2 = 11.9%) with PF showing higher variance explanation in future depression severity than vice versa. Results offer specific targets for interventions: assessment of PF could help to inform decisions regarding duration, goals, and intervention strategies beyond the treatment of personality disorders. We contextualize the results within the limitations of the study, notably the use of a single method.