TIDES 2.0: A protocol for examining the prevalence and longitudinal course of depression, anxiety and behaviour problems in children with cystic fibrosis under 12 years of age.

INTRODUCTION: Integration of mental health screening and treatment into cystic fibrosis (CF) care has been driven by the finding of elevated rates of depression and anxiety in The International Depression/Anxiety Epidemiological Study (TIDES), international mental health guidelines and CF Foundation support to screen adolescents and adults in all US CF care centres. Benefits of screening include earlier identification, greater access to care, reduced stigma and positive uptake from the CF community. However, TIDES did not include children under 12 years. Depression and anxiety have increased dramatically in young children, and new guidelines recommend mental health screening of children in primary care. Given the paediatric mental health crisis and the widespread adoption of CF transmembrane conductance regulator (CFTR) modulators, which have been associated with adverse events (AEs), there is an urgent need to gather mental health data in young children with CF. METHODS AND ANALYSIS: TIDES 2.0 is a longitudinal cohort study designed to evaluate the prevalence of depression, anxiety and behaviour problems in US children with CF 18 months through 11 years, evaluate and compare the performance of two widely used instruments to identify the optimal screening measures for this population and characterise neuropsychiatric AEs associated with CFTR modulator therapy. Purposive randomised sampling is used to recruit 600 children at 16 CF centres across 4 regions of the US, with oversampling of minoritised patients to ensure national representation. We will estimate the prevalence of children above the clinical cut-score on each symptom domain and evaluate their longitudinal course and predictors. Rigorous mixed-methods approaches will be used to describe potential AEs associated with modulator use. ETHICS AND DISSEMINATION: This study is a timely step in understanding the mental health of young children with CF. It will provide the groundwork to extend mental health screening and care to younger children with CF and inform updates to the mental healthcare guidelines. These results will be distributed at international CF meetings and submitted to peer-reviewed journals. The University at Buffalo Institutional Review Board approved the study (STUDY00008868). TRIAL REGISTRATION NUMBER: NCT07048574.