Our findings revealed no main effect of COMT Val<sup>158</sup>Met, AKT1 rs2494732 and DRD2rs1076560 polymorphisms on psychosis case status or reports of childhood adversity.
The dopaminergic hypothesis of schizophrenia (SZ) postulates that positive symptoms of SZ, in particular psychosis, are due to disturbed neurotransmission via the dopamine (DA) receptor D2 (DRD2).
Our results provide evidence that the <i>AKT1</i> gene modulates both striatal DRD2 availability and dopamine release in the human brain, which could account for its association with schizophrenia and psychosis.
RNA and DNA extracted from the saliva samples of patients with methamphetamine dependency with and without psychosis as well as control subjects (each group 25) were analyzed for expression and promoter DNA methylation status of DRD1, DRD2, DRD3, DRD4, MB-COMT, GAD1, and AKT1 using qRT-PCR and q-MSP, respectively.
The effect of two DRD2 SNPs on cognitive performance may differ according to risk type for psychosis, suggesting that cognitive intermediate phenotypes differ according to the type (familial or clinical) risk for psychosis.
We genotyped (1) a case-control study of 272 patients with their first episode of psychosis and 234 controls, and also from (2) a sample of 252 healthy subjects, for functional variation in DRD2, rs1076560.
Here, we measured the mRNA expression status of dopamine receptor D2 (DRD2), DRD3, and dopamine and cyclic adenosine 3',5'-monophosphate regulated phosphoprotein-32 (DARPP-32) in T lymphocytes of patients with early psychosis by quantitative real-time polymerase chain reaction (q-PCR) and explored the relationships between their mRNA levels and the psychopathological status of patients.
Thus, we suggest that genetic modulation of DRD2-AKT1-related prefrontal-subcortical circuits could at least in part influence cognitive dysfunction in psychosis and its treatment.
The A1/A1 homozygote of DRD2 was a negative risk factor for a poorer prognosis of psychosis that continues for more than 1 month after the discontinuance of methamphetamine abuse and the beginning of treatment with neuroleptics (p=0.04, odds ratio (OR)=0.42, 95% CI; 0.27-0.65) and the complication of spontaneous relapse of methamphetamine psychosis after remission (p=0.014, OR=0.34, 95% CI; 0.22-0.54).
rs4680" genes_norm="1312">Val158Met (rs4680, COMT), Taq IA (rs1800497, DRD2) and rs6280" genes_norm="1814">Ser9Gly (rs6280; DRD3) polymorphisms were analyzed in a sample of 84 adolescent Caucasian patients with first-episode psychosis (ages 11-17) and 85 healthy Caucasian controls (ages 10-17).
Because the mode of action of (-)-OSU6162 is critical in determining whether psychosis is associated with dopamine D2 receptor overactivity or deficit activity, we measured the potency of (-)-OSU6162 on the binding of [3H]domperidone and on the incorporation of [35S]-GTP-gamma-S into human cloned dopamine D2 receptor-containing cells.
Therefore, we examined the association between the TaqI A polymorphism of the DRD2 gene and the brain MRI view for patients with methamphetamine psychosis.
Genetic polymorphisms of D2-like dopamine receptor genes, DRD2 TaqI A, DRD3 Ser-9-Gly, and DRD4 exon III variable number of tandem repeats, were compared between: (a) MAMP users as a whole and 435 normal controls, and (b) those 154 individuals with MAMP-induced psychosis and the 252 MAMP users with no psychosis.
Therefore, in order to identify variant dopamine D2 receptors, we searched for mutations in the RNA transcripts for the dopamine D2 receptor in the striatum of post-mortem brains from individuals who died with psychosis, including schizophrenia.