This is a longitudinal, observational epidemiological study designed to estimate the prevalence of depression, anxiety, and behavior problems in children ages 18 months through 11 years with cystic fibrosis (CF).

Integration of mental health (MH) screening and treatment into cystic fibrosis (CF) care represents over 10 years of research and clinical progress, driven by elevated rates of depression and anxiety in the International Depression Epidemiological Study, MH guidelines, and CF Foundation implementation support to screen adolescents and adults in all CF Centers. 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 with CF under 12 years. Depression and anxiety have increased dramatically in young children, with new guidelines for MH screening of children in primary care. Given the pediatric MH crisis and the widespread adoption of cystic fibrosis fibrosis transmembrane conductance regulator (CFTR) modulator therapy, which have been associated with adverse events, there is an urgent need to gather MH data in children with CF <12 years. Thus, the goals of this study are to evaluate the national, longitudinal prevalence of depression, anxiety, and behavior problems in children with CF 18 months through 11 years, evaluate and compare the performance of two widely used brief screeners (criterion validity, sensitivity, specificity) to identify the optimal measures for this population, and characterize neuropsychiatric adverse events (AEs) associated with CFTR modulator therapy in this age group. Purposive randomized sampling will be used to recruit 600 children (half 18 mos.-5 yrs. and half 6-11 yrs.) at 16 CF Centers across the US. This study will estimate the prevalence of children above the clinical cut-score on each symptom domain (depression, anxiety, behavior problems) and evaluate their longitudinal course and predictors. Rigorous mixed methods will be used to describe any potential AEs perceived by parents or children to be associated with CFTR modulator therapy. This study will provide the groundwork to extend mental health screening and care to younger children with CF.

Inclusion Criteria:

1. Child with a diagnosis of Cystic fibrosis (CF) actively followed by the CF care team at a participating site
2. Child is age 18 months thru 11 years
3. English and/or Spanish speaking
4. Parent/legal guardian willing and able to give informed consent, and for minor participants ages 7 thru 11 years able to give assent.

Exclusion Criteria:

• Unable or unwilling to participate in study procedures, or at Site PI discretion.

Children with Cystic Fibrosis between 18 months and 11 years

An application process will be established for external data requests. Initially, data access will be granted upon request by Brown University Health (BUH), with full public access only after a defined period following study completion.

Beyond academic publications, BUH will contribute to the creation of publicly available study summaries, ensuring that key findings are accessible to the CF community, healthcare providers, and patient advocacy groups.