In order to test this hypothesis, we examined fasting, morning plasma concentrations of beta-endorphin and two catecholamine metabolites in prepubertal boys naive to drugs of abuse and at elevated familial risk for a substance use disorder (SA+), and in controls (SA-).
The DRD2 A1 allele was present in 73.9% of the obese subjects with comorbid substance use disorder compared to 23.5% in obese subjects without comorbid substance use disorder.
Analysis of the available data suggests that the DRD2 variants represent one of the most prominent single-gene determinants of susceptibility to severe alcoholism and other substance use disorders.
Furthermore, sib pair analysis incorporating information across all three sib pair categories: concordant affected, discordant and concordant unaffected revealed no effect of DRD2 genotype or haplotype on alcoholism or substance use disorder.
The identification of phenotypes of DRD2 genotypes suggests that the observed intronic DRD2 mutations may have functional consequences that predispose individuals to a variety of substance use disorders.
Fathers of preadolescent boys (ages 10 through 12 years) were recruited to represent families of boys with paternal SUD (High Risk or HR: N = 102) and boys without paternal SUD (Low Average Risk or LAR: n = 166).
However, a meta-analysis of a large number of Caucasian alcoholics (both more severe and less severe) and controls (both assessed and unassessed for substance use disorders) revealed a significantly higher frequency (p < 10(-6)) and prevalence (p < 10(-8)) of the DRD2 A1 allele in the alcoholics.
Because the D2 dopamine receptor (DRD2) A1 allele has been associated with alcoholism and other substance use disorders, negative affect, measured by the Beck Depression Inventory (BDI), was determined in four groups of children: boys and girls with the A1+ allele (A1A1 and A1A2 genotypes) and with the A1- allele (A2A2 genotype).
Overall, our results, albeit not definitive, are consistent with the hypothesis that variants in MAOA account for a small portion of the variance of SUD risk, possibly mediated by liability to early onset behavioral problems.
Our data suggest that a decreased expression of the gene encoding the 5-HTT transporter, due to "S" promoter polymorphism, may be associated with an increased risk for substance use disorders, particularly in the subjects with more consistent aggressiveness and impulsiveness.
The data from this study provide evidence that paternal SUDs (HAR vs. LAR status) is associated with poor dental condition, poor oral hygiene, a greater need for dental treatment, and inadequate levels of dental treatment utilization.
The data from this study provide evidence that paternal SUDs (HAR vs. LAR status) is associated with poor dental condition, poor oral hygiene, a greater need for dental treatment, and inadequate levels of dental treatment utilization.
An association of genotype distribution and allele frequency of the 5-HTR1A C(-1019)G locus was observed in schizophrenia (chi2=9.51, d.f.=2, p=0.009; chi2=9.52, d.f.=1, p=0.002; Armitage's trend test: chi2=9.07, d.f.=1, p=0.003), in substance use disorder (chi2=8.41, d.f.=2, p=0.015; chi2=8.35, d.f.=1, p=0.004; Armitage's trend test: chi2=6.27, d.f.=1, p=0.0012), and in panic attack (chi2=6.31, d.f.=2, p=0.043; chi2=6.14, d.f.=1, p=0.013; Armitage's trend test: chi2=6.27, d.f.=1, p=0.012).
Serotonin transporter promoter polymorphism (5-HTTLPR) genotype was previously found associated with substance use disorders, particularly in the subjects with comorbid antisocial behavior, and with temperament and personality traits at risk for substance abuse.
Imaging gene-substance interactions: the effect of the DRD2 TaqIA polymorphism and the dopamine agonist bromocriptine on the brain activation during the anticipation of reward.
On the whole, our preliminary data suggest that the association between 5-HT transporter polymorphism and psycho-stimulant use may be mediated by mother-child relationship and parental attachment perception, both being environmental and genetic factors involved in the proneness to substance use disorders, particularly in aggressive-antisocial individuals.