SSD-12 somatic symptom disorder scale: replication of validation and introduction of a parent version SSD-12-P

According to DSM-5, Somatic Symptom Disorder (SSD) is characterized by distressing somatic symptoms with accompanying excessive thoughts, feelings, or behaviors. SSD is highly prevalent in the adult population and imposes significant clinical and societal burden. Early identification and standardized assessments are highly relevant, particularly for effective treatment. The SSD-12 is a validated self-report measure focused on the B-criteria of SSD; however, analogues parent-reported instruments for concerns about children's somatic symptoms are lacking. Moreover, independent replications of the SSD-12's factor structure and psychometric performance in new samples remain limited, which is essential to support its routine screening use. To address these gaps, this study (1) re-examined the factor and psychometric quality of the SSD-12 in adults and (2) validated a newly developed parent version (SSD-12-P) assessing parental stress triggered by child somatic symptoms. In an online study, 564 adults and a subsample of 144 parents completed the respective instruments. Confirmatory factor analyses supported the established three-factor structure (behavioral, cognitive, affective) for both, the SSD-12 and SSD-12-P, with strong factor loadings and high internal consistencies. SSD-12 and SSD-12-P demonstrated robust convergent validity via correlations with health anxiety (WI-7) and with each other. Findings support the SSD-12's reliability for adult screening and introduce the SSD-12-P as a promising instrument to capture parental contributions to intergenerational somatic symptom burden, with implications for targeted interventions and future longitudinal research.