Do Hyperactive Symptoms Matter in ADHD-I Restricted Phenotype?

Abstract

The objective of the current study was to evaluate a proposed restrictive inattentive type of Attention Deficit Hyperactivity Disorder (ADHD) by comparing clinical correlates among youths with ADHD inattentive type (ADHD-I) as a function of the number of hyperactivity symptoms presented (none vs. 3 or less) and controls (individuals without ADHD). The sample for this community-based study was comprised of youths aged 6 to 18 years from 12 public schools in Porto Alegre, Brazil. ADHD-I groups had lower levels of adaptive functioning (p < .001) and a higher occurrence of familial ADHD (p < .001) when compared with the controls. There was no significant difference between the two ADHD-I groups. Also, both ADHD-I groups had higher rates of oppositional defiant disorder than controls (p < .001) without significant difference between them. For generalized anxiety disorder and social phobia, only the ADHD-I without HI group showed significant differences compared to controls.

We thank Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil), and Fundação de Amparo a Pesquisa do Estado de São Paulo (FAPESP) for financial support.

Notes

Note. IQ = intelligence quotient; ADHD = Attention Deficit Hyperactivity Disorder; SES = socioeconomic status.

^a Effect size calculated between the two ADHD groups for the continuous variables.

^b Statistical difference against controls.

Note. ADHD = Attention Deficit Hyperactivity Disorder; CGAS = clinical global assessment scale; ODD = oppositional defiant disorder; CD = conduct disorder; GAD = generalized anxiety disorder; SAD = separation anxiety disorder.

^a Effect size calculated between the two ADHD groups for the continuous variables.

^b Adjusted for IQ and ethnicity.

*Statistical difference against controls—Tukey for CGAS; chi-square for other variables.

Note. ADHD = Attention Deficit Hyperactivity Disorder.

^a Adjusted for IQ.

Dr. Rohde was on the advisory board/speakers bureau for Eli Lilly, Janssen-Cilag, Novartis, and Shire in the last 3 years. He received travel support for two medical meetings from Janssen-Cilag and Novartis in the same period. The ADHD and Juvenile Bipolar Disorder Outpatient Programs chaired by him received unrestricted educational and research support from the following pharmaceutical companies in the last 3 years: Abbott, Bristol-Myers Squibb, Eli-Lilly, Janssen-Cilag, Novartis, and Shire. Dr. Schmitz is on the speakers' bureau of Novartis and Janssen-Cilag.