16.5 Prevalence and Transitions of Anxiety Disorders in a Longitudinal Study of Youth

Abstract

This study examines the prevalence and transitions over time of anxiety disorders in youth in a longitudinal, community-based sample in South Carolina. Data were collected in a multistage (screening and diagnosis) study of school-aged children with and without ADHD. Children (n = 481, ages 5-13 years at baseline) and parents completed the DISC-IV at baseline, including modules for anxiety disorders. Of these, 379 (79%) participated in at least 1 of 4 annual follow-up interviews. Children met the criteria for an anxiety disorder if they met the DSM-IV criteria and had parent- or self-report of at least moderate impairment. Data are grouped by age (early childhood [EC] 5-8, late childhood [LC] 9-11, early adolescence [EA] 12-14, late adolescence [LA] 15-19) over time, and followed transitions in anxiety diagnoses. Data are weighted to reflect the sampled population and provide prevalence estimates for all diagnoses. Transition numbers are unweighted. Children can be represented more than once in the various age groups. Separation anxiety disorder had the highest prevalence (8.7%) in the youngest children, and it decreased with increasing age (1.3% in LA). Generalized anxiety followed a similar pattern (2.4%, then decreasing), while social phobia started low (1.0%) and then increased to 3.9% in ages 9-11, and 3.2% in ages 15-19. Diagnoses in early and middle childhood most often transitioned to no diagnosis in the next developmental stage (60% and 68%), while early adolescent diagnoses more often transitioned to the same or another anxiety diagnosis (61%). There were 26 children with 34 incident diagnoses in the 354 children with no diagnosis at the baseline evaluation. The incident diagnoses include 3 with generalized anxiety (2 in EA and 1 in LA), 9 with separation anxiety (1 in LC, 7 in EA, and 1 in LA), 11 with social phobia (2 in LC, 4 in EA and 5 in LA), 10 with OCD (2 in LC, 6 in EA, and 2 in LA), and 1 with PTSD (EA). Of the 9 separation anxiety incident cases, 7 were comorbid with another diagnosis. The prevalence of anxiety disorders changes throughout childhood, with separation anxiety predominant in early childhood and social phobia higher at later ages. Anxiety diagnoses in early and middle childhood tend to be more transient, whereas adolescent diagnoses are more stable over time.