Behavioral inhibition in childhood: a risk factor for anxiety disorders.

Childhood antecedents of anxiety disorders in adulthood remain poorly understood. We have, therefore, examined from longitudinal and familial perspectives the relationship between behavioral inhibition in children and anxiety disorders. We review a series of studies describing the association between behavioral inhibition and anxiety disorders in two independently ascertained and previously described samples of children. One sample was cross-sectional and clinically derived (Massachusetts General Hospital at-risk sample), and the other was epidemiologically derived and longitudinal (Kagan et al. longitudinal cohort). Our studies have found that (1) children of parents with panic disorder with agoraphobia, either alone or comorbid with major depressive disorder, are at increased risk for behavioral inhibition; (2) children identified as having behavioral inhibition have high rates of childhood-onset anxiety disorders themselves; (3) behavioral inhibition is associated with familial risk for anxiety disorders; (4) children with behavioral inhibition and anxiety disorders have greater familial loading of anxiety disorders; (5) children who remain inhibited over time are at highest risk for anxiety disorders in themselves and their families; and (6) these differences between inhibited children and not-inhibited controls become more robust at 3-year follow-up. Our research strongly indicates that behavioral inhibition is an identifiable early childhood predictor of later anxiety disorders.