Personal identity, somatic symptoms, and symptom-related thoughts, feelings, and behaviors in adolescence: Examining between- and within-person associations and the role of depressive symptoms.

Recent literature highlights the complex relationship between personal identity and body-related pathology, yet there is a lack of integrative longitudinal research on the relationship between identity and somatic symptoms. The present study investigated the longitudinal associations between identity functioning and (psychological characteristics of) somatic symptoms, and examined the role of depressive symptoms in this relationship. A total of 599 community adolescents (Time 1: 41.3% female; M age  = 14.93, SD = 1.77, range = 12-18 years) participated in three annual assessments. Using cross-lagged panel models, a bidirectional relationship between identity and (psychological characteristics of) somatic symptoms, mediated by depressive symptoms, emerged at the between-person level; whereas only a unidirectional relationship from psychological characteristics of somatic symptoms to identity functioning, mediated by depressive symptoms, emerged at the within-person level. Identity and depressive symptoms were bidirectionally related at both levels. The present study suggests that adolescent identity development is closely related to somatic and emotional distress.