[From inattentive-type attention deficit hyperactivity disorder to the restrictive type]

Attention deficit hyperactivity disorder (ADHD) is a very heterogeneous neurobiological condition. It is the most common neurodevelopmental disorder in the childhood population. Its prevalence is estimated to be 3-6% in school-age children. AIM. To review the characteristics of patients with inattentive subtype ADHD, including those who could be grouped in a more homogenous subtype which the DSM-5 proposes for classification as the restrictive subtype.

The characteristic triad of symptoms consists of attention deficit, hyperactivity and impulsivity. The diagnostic criteria are defined in the DSM-IV-TR. For those with deterioration due to ADHD with no significant hyperactivity problems, this manual offers a confusing diagnostic label. Indeed, the neurobiological substrate underlying the diverse subtypes seems to be different in certain aspects, since the frontostriatal circuit appears to be more affected in combined ADHD, while the frontoparietal circuit is more compromised in the inattentive subtype. For these and other reasons, the DSM-5 will reformulate the different subtypes of ADHD and will probably include a new subgroup that will comprise those patients who satisfy at least six inattention criteria and fewer than two criteria for hyperactivity-impulsivity (restrictive ADHD).

The definition of this subgroup could make it easier to detect some patients who have so far received little attention from the point of view of both research and clinical practice.