Characterization and Prediction of Anxiety in Adolescents with Autism Spectrum Disorder: A Longitudinal Study.

Anxiety is one of the most common comorbidities in youth with autism spectrum disorder (ASD). The current study's aims were: To examine the frequency of elevated anxiety symptoms in adolescents diagnosed with ASD in toddlerhood; To explore the impact of comorbid anxiety in adolescents on clinical presentation; To evaluate variables in toddlerhood that associate with anxiety symptom severity in adolescence. The study included 61 adolescents (mean age = 13:8y) diagnosed with ASD in toddlerhood (T1). Participants underwent a comprehensive assessment of cognitive ability, adaptive skills and autism severity at T1 and again as adolescents (T2), and an evaluation of anxiety symptoms at T2. For the first aim, the most prevalent anxiety subtypes noted in adolescence were separation (39.3%), social (27.9%) and generalized anxiety (18.0%). For the second aim, cognitive ability, autism severity and adaptive skills in adolescents with and without elevated anxiety symptoms scores of any type did not differ significantly. For the third aim, younger age at adolescence was associated with more severe separation and generalized anxiety symptoms. Higher cognitive ability and adaptive skills in toddlerhood were associated with elevated generalized anxiety symptoms in adolescence. Lower adaptive behaviors and repetitive behaviors (RRBs) correlated with elevated social anxiety symptoms. Lower cognitive abilities and more severe RRBs in toddlerhood predicted separation anxiety in adolescence. The study sheds light on early characteristics in ASD that associate with anxiety symptom severity in adolescence. The type of elevated anxiety symptoms presented in adolescence associated with the level of cognitive ability, adaptive skills and RRBs in toddlerhood.