Anxiety symptom trajectories from treatment to 5‐ to 12‐year follow‐up across childhood and adolescence

Objective The current study examined trajectories of anxiety during (a) acute treatment and (b) extended follow‐up to better characterize the long‐term symptom trajectories of youth who received evidence‐based intervention for anxiety disorders using a person‐centered approach. Method Participants were 319 youth (age 7–17 years at enrollment), who participated in a multicenter randomized controlled trial for the treatment of pediatric anxiety disorders, Child/Adolescent Anxiety Multimodal Study, and a 4‐year naturalistic follow‐up, Child/Adolescent Anxiety Multimodal Extended Long‐term Study, an average of 6.5 years later. Using growth mixture modeling, the study identified distinct trajectories of anxiety across acute treatment (Weeks 0–12), posttreatment (Weeks 12–36), and the 4‐year‐long follow‐up, and identified baseline predictors of these trajectories. Results Three nonlinear anxiety trajectories emerged: “short‐term responders” who showed rapid treatment response but had higher levels of anxiety during the extended follow‐up; “durable responders” who sustained treatment gains; and “delayed remitters” who did not show an initial response to treatment, but showed low levels of anxiety during the maintenance and extended follow‐up periods. Worse anxiety severity and better family functioning at baseline predicted membership in the delayed remitters group. Caregiver strain differentiated short‐term responders from durable responders. Conclusions Findings suggest that initial response to treatment does not guarantee sustained treatment gains over time for some youth. Future follow‐up studies that track treated youth across key developmental transitions and in the context of changing social environments are needed to inform best practices for the long‐term management of anxiety.