Sensory profiles in adults with and without ADHD.

BACKGROUND: Our previous work demonstrates that adults with ADHD produce more force at the fingertips compared to adults without ADHD. One possibility is that somatosensation is impaired in ADHD. However, ADHD is often comorbid with anxiety, and anxiety influences sensory responsivity. AIMS: The goal of the current work was to evaluate differences in the self-report of sensory experiences in adults with and without ADHD, while controlling for internalizing behaviors. METHODS AND PROCEDURES: Forty-five adults (23 with ADHD) completed a semi-structured interview for the diagnosis of ADHD, the Adolescent/Adult Sensory Profile (AASP), and the Achenbach Adult Self Report (ASR). OUTCOMES AND RESULTS: Adults with ADHD reported more hyper- and hypo- sensitivity compared to adults without ADHD, even when controlling for internalizing behaviors. Specifically, between group differences were found for low registration, sensation seeking, and sensory sensitivity scores, but not for sensation avoiding, and for movement, visual, touch, activity, audition, or taste/smell. CONCLUSIONS AND IMPLICATIONS: These findings demonstrate that sensory hyper- and hypo- sensitivity may be features of ADHD in adults. Further, they demonstrate that internalizing behaviors influence the perception of sensory experiences and thus should be accounted for in studies of sensory processing, integration, and modulation in adults with ADHD.

Association and linkage of alpha-2A adrenergic receptor gene polymorphisms with childhood ADHD.

Attention-deficit hyperactivity disorder (ADHD) is a heritable disorder, prevalent from childhood through adulthood. Although the noradrenergic (NA) system is thought to mediate a portion of the pathophysiology of ADHD, genes in this pathway have not been investigated as frequently as those in the dopaminergic system. Previous association studies of one candidate gene in the NA system, ADRA2A, showed inconsistent results with regard to an MspI polymorphism. In the current study, two nearby single-nucleotide polymorphisms, which define HhaI and DraI restriction fragment length polymorphisms, were also genotyped and were in significant linkage disequilibrium with the MspI RFLP. Transmission disequilibrium tests (TDTs) in a sample of 177 nuclear families showed significant association and linkage of the DraI polymorphism with the ADHD combined subtype (P=0.03), and the quantitative TDT showed association of this polymorphism with the inattentive (P=0.003) and hyperactive-impulsive (P=0.015) symptom dimensions. The haplotype that contained the less common allele of the DraI polymorphism likewise showed a strong relationship with the inattentive (P=0.001) and hyperactive-impulsive (P=0.004) symptom dimensions. This study supports the hypothesis that an allele of the ADRA2A gene is associated and linked with the ADHD combined subtype and suggests that the DraI polymorphism of ADRA2A is linked to a causative polymorphism.