Is the Inattentive Subtype of ADHD Different From the Combined/Hyperactive Subtype?

Objective: To compare the ADHD combined/hyperactive subtype (ADHD/CH) to the ADHD inattentive subtype (ADHD/I) on the level of comorbidity, treatment response, and possible etiological factors.

Method: A total of 371 clinically referred children diagnosed with ADHD aged between 6 and 12 years are recruited for a double-blind, placebo-controlled trial of methylphenidate. Comorbidity, treatment response, and stress during pregnancy are assessed for each participant. Genotyping is done for the DAT, DRD4, and 5-HTT genes. Mothers report smoking or alcohol consumption during their pregnancy and their child’s birth weight.

Results: The ADHD/CH children show both a higher frequency of conduct disorder and good response to treatment, are exposed to more moderate stress during their mothers’ pregnancy, and show a higher frequency of L/L genotype for the 5-HTT-linked polymorphic region.

Conclusion: The significant differences found between the ADHD/CH and the ADHD/I subtypes raise the possibility that the two may be separate disorders.


Autor:N. Grizenko, M. Paci, R. Joober
Quelle:Journal of Attention Disorders, 13 (6), 2009, 649-657
Keywords (deutsch):---
Keywords (englisch):ADHD subtypes, treatment response, etiology