Objective: This study examined the hypothesis that individuals
with attention deficit hyperactivity disorder, predominantly inattentive type (ADHD-I),
show both executive function (EF) deficits and non-EF deficits. Method: A group with ADHD-I (n = 16)
and a paired control group (n = 21) completed a battery of tasks covering the
major domains of EF (planning, working memory, flexibility and inhibition) and
non-EF (alertness, divided
attention, flexibility, sustained attention, visual field and visual scanning). Results: EF impairments in planning, spatial working memory,
flexibility, and inhibition as well as non-EF impairments in divided attention,
flexibility, sustained attention and visual scanning were observed in the
ADHD-I group. Conclusion: Our results do not support the traditional model of
ADHD. Given that neither EF nor non-EF tests typically distinguish ADHD-I from
ADHD-C, alternative methodologies are required to confirm the validity of ADHD subtypes in the Diagnostic
and Statistical Manual of Mental Disorders, Fourth Edition.