After adjustment for other covariates, children who carried the DRD4 GG genotype, had been exposed to high DMP levels (more than the median), and had high HNE-MA levels had a significantly increased risk for developing ADHD (OR = 11.74, 95% CI: 2.12-65.04).
A positive association was found with the DRD2 and DRD4 polymorphisms in the subgroups of patients with childhood ADHD, or with a high impulsivity score, which represented, respectively, 53.3 and 73.0% of the patients.
An initial report of association between ADHD and the common 148-bp allele of a microsatellite marker located 18.5 kb from the DRD5 gene has been followed by several studies showing nonsignificant trends toward association with the same allele.
The seven repeat allele of the DRD4 48-bp repeat polymorphism (DRD4.7) was not significantly associated with ADHD in the large sample in contrast to our earlier findings in a smaller subset.
We replicate an association of a dinucleotide repeat polymorphism near the DRD5 gene with ADHD by showing biased nontransmission of the 146-bp allele (P=0.02) and a trend toward excess transmission of the 148-bp allele (P=0.053).
The dopamine D4 receptor is essential for hyperactivity and impaired behavioral inhibition in a mouse model of attention deficit/hyperactivity disorder.
These provisional findings suggest that newly developed COMT inhibitors such as tolcapone, applied in Parkinson's disease, might in due time be considered in the treatment of ADHD.
A deletion within the glutamate receptor gene, GRM5, was found in an affected parent and all three affected offspring whose ADHD phenotypes closely resembled those of the GRM5 null mouse.
We suggest that FGD1 analysis may be adequate in ADHD patients who exhibit dysmorphic features suggestive of AAS, also in the absence of the full phenotypical spectrum.
Mutations in LPHN3 are strongly associated with attention deficit hyperactivity disorder, suggesting a role for latrophilins in human cognitive function.
As striatal DA signalling modulates the endocannabinoid system (ECS), the present study was aimed at investigating cannabinoid CB1 receptor (CB1R) function in a model of ADHD obtained by triple point-mutation in the dopamine transporter (DAT) gene in mice, making them insensitive to cocaine [DAT cocaine-insensitive (DAT-CI) mice].
A positive association was found with the DRD2 and DRD4 polymorphisms in the subgroups of patients with childhood ADHD, or with a high impulsivity score, which represented, respectively, 53.3 and 73.0% of the patients.
Among the several polymorphisms already described in the SLC6A3 locus, a 40 bp variable number of tandem repeats (VNTR) polymorphism has been extensively investigated in association studies with ADHD.
Efficacy and safety of the novel α₄β₂ neuronal nicotinic receptor partial agonist ABT-089 in adults with attention-deficit/hyperactivity disorder: a randomized, double-blind, placebo-controlled crossover study.
Our results point to CB1Rs as novel molecular players in ADHD, and suggest that therapeutic strategies aimed at interfering with the ECS might prove effective in this disorder.