Performance-only Social Anxiety as a Distinct Clinical Profile: Evidence from Obsessive Beliefs, Alexithymia, and...

Social anxiety disorder (SAD) in adolescent girls is clinically heterogeneous, yet the cognitive and emotional processes distinguishing performance-based, interaction-based, and combined presentations remain poorly characterized. In this case-control study, 219 adolescent girls aged 12-18 years were recruited from four child and adolescent psychiatry outpatient clinics and assigned, via K-SADS-PL-guided diagnostic evaluation, to four groups: performance anxiety only (SA - PA+; n = 52), social interaction anxiety only (SA + PA-; n = 50), combined social interaction and performance anxiety (SA + PA+; n = 67), and healthy controls (n = 50). Groups were compared on clinician-rated severity, social anxiety symptoms, obsessive beliefs (OBQ-44), alexithymic traits (TAS-20), and cognitive flexibility (CFI). A gradient boosting classifier, complemented by a sensitivity analysis excluding direct severity indicators, examined whether the three clinical phenotypes remained distinguishable beyond overall symptom load. Clinician-rated global severity (CGI-S) did not differ across the clinical groups, whereas the three presentations diverged across multiple cognitive-emotional domains, with large omnibus effects (ε² = 0.16-0.25). The SA - PA+ group showed lower obsessive beliefs and relatively preserved cognitive flexibility; the SA + PA- group was distinguished by reduced flexibility in generating alternative interpretations; the SA + PA+ group showed elevated alexithymic traits, longer illness duration, and the highest rate of previous psychiatric referral. Gradient boosting classified the three clinical groups with high cross-validated accuracy (0.96; macro-F1 = 0.96), decreasing only modestly when severity indicators were excluded (0.93). Performance-only, interaction-only, and combined SAD presentations reflect partially distinct cognitive-emotional profiles rather than a single severity gradient, which may inform assessment, case formulation, and treatment planning.