Reciprocal relations between dimensions of attention-deficit/hyperactivity and anxiety disorders from preschool age to adolescence: sex differences in a birth cohort sample.

Background: Symptoms of anxiety and attention-deficit/hyperactivity disorder (ADHD) are prospectively related from childhood to adolescence. However, whether the two dimensions of ADHD-inattention and hyperactivity-impulsivity-are differentially related to anxiety and whether there are developmental and sex/gender differences in these relations are unknown.

Methods: Two birth cohorts of Norwegian children were assessed biennially from ages 4 to 16 (N = 1,077; 49% girls) with diagnostic parent interviews used to assess symptoms of anxiety and ADHD. Data were analyzed using a random intercept cross-lagged panel model, adjusting for all unobserved time-invariant confounding effects.

Results: In girls, increased inattention, but not hyperactivity-impulsivity, predicted increased anxiety 2 years later across all time-points and increased anxiety at ages 12 and 14 predicted increased inattention but not hyperactivity-impulsivity. In boys, increased hyperactivity-impulsivity at ages 6 and 8, but not increased inattention, predicted increased anxiety 2 years later, whereas increased anxiety did not predict increased inattention or hyperactivity-impulsivity.

Conclusions: The two ADHD dimensions were differentially related to anxiety, and the relations were sex-specific. In girls, inattention may be involved in the development of anxiety throughout childhood and adolescence and anxiety may contribute to girls developing more inattention beginning in early adolescence. In boys, hyperactivity-impulsivity may be involved in the development of anxiety during the early school years. Effective treatment of inattention symptoms in girls may reduce anxiety risk at all time-points, while addressing anxiety may decrease inattention during adolescence. Similarly, treating hyperactivity-impulsivity may reduce anxiety risk in boys during late childhood (at ages 8-10).