Neuropsychological differences between attention deficit hyperactivity disorder and control children and adolescents referred for academic impairment

Abstract

To compare the performances of children and adolescents with attention deficit hyperactivity disorder with a group of control comparison subjects, both taken from a large clinical sample, using some of the most widely employed attention-based Brazilian tests. The performances of 186 children and adolescents with attention deficit hyperactivity disorder were compared to that of 80 control individuals based on attention and working memory scores. Both groups had been referred due to academic impairment. All individuals were submitted to the TAVIS-3 sustained, shifted and focused attention tests, as well as to the working memory tests that make up the WISC-III Freedom from Distractibility Index (Digit Span and Arithmetic). The control group was slightly older than the attention deficit hyperactivity disorder group (p = 0.07); IQ and schooling did not differ between groups (p = 0.34 and p = 0.38, respectively). While performing a test requiring sustained attention for a longer period of time, the attention deficit hyperactivity disorder group showed a significantly higher number of commission errors compared to the controls, thus presenting sustained attention deficits (p = 0.003); when the influence of IQ, age and schooling was reduced, the attention deficit hyperactivity disorder group also made more omission errors during a sustained attention task in comparison to the control group, thus achieving a borderline significance level (p = 0.08); the attention deficit hyperactivity disorder group also performed worse in Digit Span forward and backward (p = 0.013 and p = 0.01, respectively) and in Arithmetic (p = 0.008). Other scores did not achieve significance. Our findings suggest that some of the most commonly used Brazilian attention-based tests - especially the sustained attention and working memory tests - may be useful to help distinguish subjects with attention deficit hyperactivity disorder from control subjects.