Attentional difficulties in hyperactive and conduct-disordered children: a processing deficit.

A random population sample of 1479 Chinese boys from Hong Kong was screened and diagnosed in a two-stage epidemiological study. Four groups, age 7-8, were distinguished: (1) a pure hyperactive group (HA), (2) a mixed hyperactive/conduct-disordered group (HA+CD), (3) a pure conduct-disordered group (CD), and (4) a normal control group (N).

On a visual search task, only the pure hyperactive (HA) children showed a specific processing deficit in performance.

• This confirms the diagnostic value of such a deficit for hyperactivity, differentiating it from conduct disorder.
• The failure to find a similar deficit in the HA+CD group raises questions concerning the clinical identity of these children.

Each group showed a performance decrement over time in the visual search task but the decrement did not differ between the four groups. This observation is not congruent with the reports of a short attention span in hyperactive children; explanations of this apparent contradiction are considered.

J Child Psychol Psychiatry 1994 Oct;35(7):1229-45
Leung PW, Connolly KJ
Department of Psychology,
Chinese University of Hong Kong, Shatin, New Territories.