Background Youth with chronic physical illness (YwCPI) are more vulnerable to developing psychopathology than their healthy counterparts. Families are negatively impacted by CPI diagnosis; however, research has neglected siblings. This study assessed the continuity of symptoms of psychopathology in YwCPI and siblings. Methods Data come from MY LIFE, a prospective study that includes five waves (T1 through T5) among 171 YwCPI and their siblings. Two cross-lagged panel models were computed to evaluate continuity of internalizing and externalizing symptoms. Autoregressive pathways measured homotypic continuity by predicting changes in the same outcome across assessments, while cross-lagged pathways appraised heterotypic continuity by testing if one symptom predicted another at later time points. Results Significant ( p < 0.05) autoregressive paths were detected between all time points for internalizing (YwCPI: β = 0.22–0.78; sibling: β = 0.23–0.75) and externalizing (YwCPI: β = 0.40–0.75; sibling: β = 0.26–0.78) symptoms. In YwCPI, internalizing symptoms at T1 predicted externalizing symptoms at T2, while in siblings an indirect effect was observed from T1 externalizing to T2 internalizing symptoms. Conclusion Homotypic continuity was strong and similar for YwCPI and siblings. Patterns of heterotypic continuity were of smaller magnitude and differed between the two groups. The presence of internalizing and externalizing symptoms in YwCPI and siblings support the inclusion of siblings in family-centred care.
Basque et al. (2026) studied this question.