AbstractIntroductionReports of neuropsychiatric symptoms proximal to cystic fibrosis transmembrane conductance regulator (CFTR) modulator initiation are emerging, but their prevalence and management remain poorly characterized.MethodsRetrospective chart review was used to categorize symptom trajectories of all adults at a single CF Center who initiated elexacaftor/tezacaftor/ivacaftor (ETI) before March 2022 and subsequently had ≥1 outpatient visit with the consulting CF psychiatrist. For those who developed neuropsychiatric symptoms probably related to ETI and modified treatment in response, the strategy resulting in greatest improvement with acceptable physical course and tolerability was identified. Ratings were made by a psychiatrist not involved in clinical care.ResultsOf 148 adults initiating ETI, 31 were psychiatrically evaluated, 16 of whom developed new/worsening and unexpected neuropsychiatric symptoms probably related to ETI, including neurocognitive (word finding, brain fog, memory, attention/concentration), insomnia, depression, anxiety, fatigue/low energy, mania/hypomania, other distress. This group had higher maximum lifetime Generalized Anxiety Disorder‐7 scores (14.42 ± 0.96; p = 0.05) than those with improved, unchanged, or worsening/possibly related symptoms (N = 15; 9.9 ± 1.82). Treatment strategies resulting in much/very much improvement included pharmacologic interventions, psychotherapy, and dose reduction/discontinuing ETI.ConclusionsAlthough many people initiating ETI experience improved physical and mental health and quality of life, a subset report worsening neurocognition, mood, and anxiety. As novel therapies are developed, ascertaining and evaluating neuropsychiatric symptoms in clinical and research settings is advisable. Larger studies are needed to characterize prevalence, course, and risk factors (e.g., age, gender, clinical status, pharmacokinetics/pharmacogenomics, drug−drug interactions) for neuropsychiatric adverse events related to CFTR modulators and guide effective management.