The prevalence of co-occurring anxiety and externalizing (i.e., attent
ion deficit-hyperactivity, oppositional, and conduct disorders) condit
ions is examined in both epidemiological and clinic-referred studies a
mong child and adolescent samples. In the context of comorbid anxious
and externalizing conditions, issues of age, gender, and familial diff
erences are explored. Literature that describes the associated charact
eristics of children diagnosed with comorbid anxiety and attention def
icit disorders is reviewed, followed by a similar ''view of the litera
ture with respect to comorbid anxiety and conduct disorders of childho
od. Validation issues and suggestions for improvements to future resea
rch on comorbid childhood anxiety and externalizing disorders are disc
ussed.