Purpose This work aims to prospectively study stress response symptoms (SRS) in adolescents during the first year after a parent's cancer diagnosis and factors associated with SRS. Additionally, SRS in these adolescents were compared to SRS in adolescents whose parents were diagnosed 1-5 years (reference group) previously.Methods Forty-nine adolescents, 37 ill parents, and 37 spouses completed questionnaires within 4 months after diagnosis (T1) and six (T2) and 12 months (T3) later.Results Clinically elevated SRS were found in 29% of adolescents at T1,16% at T2, and 14% at T3. In contrast, in the reference group, we found 29% clinically elevated SRS. Daughters seemed more at risk than sons. Adolescents' age, patient's gender, and intensity ...