Maladaptive perfectionism and experiential avoidance as transdiagnostic pathways between eating disorder and social anxiety symptoms in young adults

BACKGROUND: Eating disorder (ED) and social anxiety (SA) symptoms frequently co-occur and are associated with greater clinical severity and poorer outcomes. From a transdiagnostic perspective, maladaptive perfectionism and experiential avoidance have been proposed as shared vulnerability processes, yet they have rarely been examined simultaneously within integrative structural frameworks. METHODS: This study examined bidirectional associations between ED and SA symptom risk and evaluated the role of maladaptive perfectionism and experiential avoidance as transdiagnostic processes within a cross-sectional structural equation modelling framework. A non-clinical sample of 705 young adults aged 18-25 years was recruited from educational settings in Spain. Participants completed validated self-report measures assessing ED (Eating Attitudes Test-26, EAT-26; [28]) and SA symptom risk (Liebowitz Social Anxiety Scale, LSAS; [50] ), maladaptive perfectionism (concern over mistakes and personal standards) (Frost Multidimensional Perfectionism Scale, FMPS; [26]), and experiential avoidance (Personalized Psychological Flexibility Index, PPFI; [41]). Structural equation modelling with bootstrap estimation was used to estimate direct and indirect associations and to compare alternative models. RESULTS: ED and SA symptom risk showed significant bidirectional associations. Maladaptive perfectionism was consistently associated with higher ED and SA symptom risk through direct and indirect associations. Experiential avoidance exhibited a more complex pattern, characterised by negative direct associations alongside positive indirect associations with both symptom domains. Models including both transdiagnostic processes demonstrated superior fit and parsimony compared with models excluding these processes or including a single process. CONCLUSIONS: These findings highlight maladaptive perfectionism and experiential avoidance as relevant transdiagnostic processes associated with the co-occurrence of ED and SA symptoms in young adults. The results support integrative, process-focused perspectives for understanding ED-SA comorbidity and may inform assessment and formulation within transdiagnostic frameworks.