Which anxiety disorders may differentiate attention deficit hyperactivity disorder, combined type with dysthymic disorder from attention deficit hyperactivity disorder, combined type alone?

OBJECTIVE: Attention deficit hyperactivity disorder, combined type (ADHD-CT), dysthymic disorder, and anxiety disorders frequently co-occur in primary school age children, although there have been no published data describing their association. We investigated the association of anxiety, defined from a parent or child perspective, with primary school-age children with ADHD-CT with and without dysthymic disorder.
METHOD: One hundred and forty-six medication naïve children with ADHD-CT were studied. Two groups with and without dysthymic disorder were formed to compare parent and child reports of anxiety, using categorical and continuous measures of anxiety, using logistic regression.
RESULTS: Separation anxiety disorder and social phobia were associated with primary school-age children with ADHD-CT and dysthymic disorder, compared to children with ADHD-CT without dysthymic disorder.
CONCLUSIONS: The recognition of dysthymic disorder and anxiety disorders and their management in primary school-age children with ADHD-CT is generally poorly understood. The identification and elucidation of composite anxiety and depressive phenomena that may be systematically investigated through longitudinal studies of epidemiologically derived samples is needed in this particular group of children.