Attention deficit is one of the core symptoms of the
attention-deficit/hyperactivity disorder (
ADHD). However, the specific genetic variants that may be associated with attention function in adult
ADHD remain largely unknown. The present study aimed to identifying SNPs associated with attention function in adult
ADHD and tested whether these associations were enriched for specific biological pathways. Commissions, hit-reaction time (HRT), the standard error of HRT (HRTSE), and intraindividual coefficient variability (ICV) of the Conners Continuous Performance Test (
CPT-II) were assessed in 479 unmedicated adult
ADHD individuals. A Genome-Wide Association Study (GWAS) was conducted for each outcome and, subsequently, gene set enrichment analyses were performed. Although no SNPs reached genome-wide significance (P < 5E-08), 27 loci showed suggestive evidence of association with the
CPT outcomes (P < E-05). The most relevant associated SNP was located in the SORCS2 gene (P = 3.65E-07), previously associated with
bipolar disorder (BP),
Alzheimer disease (AD), and brain structure in elderly individuals. We detected other genes suggested to be involved in synaptic plasticity, cognitive function, neurological and neuropsychiatric disorders, and smoking behavior such as NUAK1, FGF20, NETO1, BTBD9, DLG2, TOP3B, and CHRNB4. Also, several of the pathways nominally associated with the
CPT outcomes are relevant for
ADHD such as the
ubiquitin proteasome,
neurodegenerative disorders, axon guidance, and AD
amyloid secretase pathways. To our knowledge, this is the first GWAS and pathway analysis of attention function in patients with persistent
ADHD. Overall, our findings reinforce the conceptualization of attention function as a potential endophenotype for studying the molecular basis of adult
ADHD. © 2015 Wiley Periodicals, Inc.