Genes and alcohol

A Real-World Study on the Use of the Alcohol Use Disorders Identification Test (AUDIT) in Men Admitted to a Psychiatric Hospital

Background

This real-world study aimed to investigate the use of the Alcohol Use Disorders Identification Test (AUDIT) in men admitted to a psychiatric hospital.

Material/Methods

The AUDIT questionnaire (10 items) was consecutively administered for a period of 3 years to male patients admitted to a psychiatric hospital (n=636). Laboratory blood tests of biochemical parameters were measured as biomarkers of alcohol consumption. Data were evaluated using linear models with mixed effects in the case of continuous dependent variables and logistic regression models with mixed effects in the case of categorical dependent variables.

Results

We found that 45.3% of the patients had a high risk of alcohol consumption or alcohol dependence and 54.7% had a low risk of alcohol consumption. The ICD-10 diagnoses of alcohol-related disorders (F1x), psychotic disorders (F2x), affective disorders (F3x), neurotic and psychosomatic disorders (F4x) were statistically significantly associated with total AUDIT score (P<0.001). There was a statistically significant association between the total AUDIT score and length of hospitalization (P=0.004) and the incidence of suicidal thoughts (P=0.003). Plasma concentrations of alanine aminotransferase (P=0.005), aspartate aminotransferase (P<0.001), gamma glutamyltransferase (P=0.001), total cholesterol (P=0.027) and mean corpuscular value of erythrocytes (P<0.001) were statistically significantly increased with a higher AUDIT score.

Conclusions

This real-world study showed that the AUDIT questionnaire evaluated the severity of disorders caused by alcohol and their impact on comorbid mental disorders. These results may be helpful in improving targeted interventions in this group of patients.

Family history of alcohol use disorder is associated with brain structural and functional changes in healthy first-degree relatives

Background:

Neuroimaging studies of vulnerability to Alcohol Use Disorder (AUD) have identified structural and functional variations which might reflect inheritable features in alcohol-naïve relatives of AUD individuals (FH+) compared to controls having no such family history (FH-). However, prior research did not simultaneously account for childhood maltreatment, any clinically significant disorder and maternal AUD. Therefore, we mainly aimed to investigate the brain structure and reward-related neural activations (fMRI), using whole-brain analysis in FH+ young adults with no prevalent confounders.

Methods:

46 FH+ and 45 FH- male and female participants had no severe childhood maltreatment exposure, neither any psychiatric disorder or AUD, nor a prenatal exposure to maternal AUD. We used a 3 T MRI coupled with a whole brain voxel-based method to compare between groups the grey matter volumes and activations in response to big versus small wins during a Monetary Incentive Delay task. The Childhood Trauma Questionnaire score was used as confounding variable in the analyses to account for the remaining variance between groups.

Results:

Compared to FH- controls, FH+ participants had smaller grey matter volumes in the frontal and cingulate regions as well as in the bilateral nucleus accumbens and right insula. The FH+ participants’ fMRI datasets denoted a blunted activation in the middle cingulum with respect to FH- controls’ during the processing of reward magnitude, and a greater activation in the anterior cingulum in response to anticipation of a small win.

Conclusions:

Family history of alcohol use disorder is linked to structural and functional variations including brain regions involved in reward processes.

[The 444G/A and -1021 C/T polymorphisms of the dopamine-beta-hydroxylase gene modulate the trajectory of alcohol dependence development]

AIM

To study the influence of 444 G/A (rs 1108580) and -1021 C/T (rs 1611115) polymorphisms of the dopamine beta-hydroxylase (DBH) gene on clinical parameters of the trajectory of alcohol dependence.

MATERIAL AND METHODS

Authors studied 548 male inpatients, of Slavic ethnicity, with ICD-10 diagnosis of «alcohol dependence» (F-10.2).

RESULTS

The effects of DBH * 444 G/A on the rate of formation of alcohol withdrawal syndrome (AWS), and DBH *-1021C/T on the age of onset of alcohol abuse with significant role of the age of first alcohol use were identified. In 444 G/A GG carriers, the development of AWS was accelerated since the beginning of alcohol abuse compared with AA carriers (p=0.026), AG carriers occupied an intermediate position. In 22.5% of GG carriers, AWS developed within 2 years (AA: 8.11%, p=0.005; AG: 17.67%, p=0.04). According to the results of linear regression analysis, in AG carriers the alcohol abuse (p=0.037) and the AWS (p=0.049) developed earlier than in AA carriers if the first alcohol use occured at the age of about 15 years. Among -1021C/T genotype carriers who began to abuse alcohol at an early age (before 20 years), there were 23.45% patients with CC genotype and only 11.97% with a T allele (genotypes CT+TT) (p=0.03), but T carriers began to abuse alcohol earlier than others (p=0.05) if the first alcohol use occurred at the age of about 16 years.

CONCLUSION

The results can be used to search for genetic markers for prognosis of alcohol dependence development.

Moderators of the association between peer and target adolescent substance use

Associating with substance using peers is generally considered as one of the most important predictors of adolescent substance use. However, peer association does not affect all adolescents in the same way. To better understand when and under what conditions peer association is most linked with adolescent substance use (SU), this review focuses on the factors that may operate as moderators of this association. The review highlighted several potential moderators reflecting adolescents' individual characteristics (e.g., pubertal status, genes and personality), peer and parental factors (e.g., nature of relationships and parental monitoring), and contextual factors (e.g., peer, school and neighborhood context). As peer association is a broad concept, important methodological aspects were also addressed in order to illustrate how they can potentially bias interpretation. Taking these into account, we suggest that, while the effects of some moderators are clear (e.g., parental monitoring and sensation seeking), others are less straightforward (e.g., neighborhood) and need to be further examined. This review also provides recommendations for addressing different methodological concerns in the study of moderators, including: the use of longitudinal and experimental studies and the use of mediated moderation. These will be key for developing theory and effective prevention.

Alcohol misuse and criminal offending: findings from a 30-year longitudinal study

BACKGROUND

This study examined the associations between measures of alcohol abuse/dependence (AAD) and several classifications of offending behaviour to age 30 in a New Zealand birth cohort.

METHODS

Outcomes included: assault; use of a weapon; theft/burglary/vehicle conversion; property damage/vandalism/arson; and fraud/embezzlement/misappropriation of funds. The study also used measures of AAD symptoms; and time-dynamic covariate factors including life stress, other substance use, mental health status, peer and partner substance use and offending, and unemployment. Data were analysed using conditional fixed effects regression modelling augmented by time-dynamic covariate factors to control for confounding.

RESULTS

Those with five or more AAD symptoms had unadjusted odds of offending that ranged from 6.23 to 21.25 times higher than those with no symptoms, with little evidence to suggest these associations varied with age. Adjustment for both unobserved fixed effects and time-dynamic covariate factors reduced the magnitude of the associations between AAD and offending, with those with five or more AAD symptoms having odds of offending that were 0.88-4.10 times higher than those with no symptoms. After adjustment, only the associations between AAD and: a) assault (OR=4.10; 95% CI=1.91-8.62; p<0.0001); and b) property damage/vandalism/arson (OR=3.87; 95% CI=1.30-11.39; p<0.0001); remained statistically significant.

CONCLUSIONS

The results suggest a causal association between alcohol misuse and "impulsive" crimes such as assault and property damage/vandalism/arson, with estimates suggesting that AAD accounted for approximately 9.6-9.9% of these types of reported offending in the cohort.

Individual differences in rhesus monkeys' demand for drugs of abuse

A relatively small percentage of humans who are exposed to drugs of abuse eventually become addicted to or dependent on those drugs. These individual differences in likelihood of developing drug addiction may reflect behavioral, neurobiological or genetic correlates of drug addiction and are therefore important to model. Behavioral economic measures of demand establish functions whose overall elasticity (rate of decrease in consumption as price increases) reflects the reinforcing effectiveness of various stimuli, including drugs. Using these demand functions, we determined the reinforcing effectiveness of five drugs of abuse (cocaine, remifentanil, ketamine, methohexital and ethanol) in 10 rhesus monkeys with histories of intravenous drug-taking. There was a continuum of reinforcing effectiveness across the five drugs, with cocaine and remifentanil showing the most reinforcing effectiveness. There was also a continuum of sensitivity of the monkeys; two of the 10 animals, in particular, showed greater demand for the drugs than did the remaining eight monkeys. In addition, monkeys that demonstrated greater demand for one drug tended to show greater demand for all drugs but did not show a similar relatively greater demand for sucrose pellets. These findings suggest that the tendency to find drugs to be reinforcing is a general one, not restricted to particular drugs and also, that a minority of animals show a substantially enhanced sensitivity to the reinforcing effects of drugs. The possibility that differences in responsiveness to the reinforcing effects of drugs may form the basis of individual differences in drug-taking in humans should be considered.

A haplotype analysis is consistent with the role of functional HTR1B variants in alcohol dependence

BACKGROUND

Animal and human studies have suggested that the serotonergic system plays an important role in alcohol consumption and abuse, mainly due to the serotonin receptor 1B (5-HT(1B)) function in the mesolimbic reward pathway. Association studies between the HTR1B gene variants and alcoholism have found significant results. There is also evidence for a complex balancing regulation of the gene by two functional variants in the promoter region (rs11568817 and rs130058), which are in linkage disequilibrium.

METHODS

The aim of this study is to investigate the role of the most relevant variants (rs11568817, rs130058, rs6296 and rs13212041) of the HTR1B gene in the susceptibility to alcohol dependence. The sample comprised 136 Brazilian alcoholics of European descendent and 237 controls.

RESULTS

The results suggest an association between a functional variant of the gene (rs11568817) and alcohol dependence (p=0.001). In addition, this association could also be confirmed in an independent sample using imputed data from a GWAS, where marginal significant association (p=0.03, one-tailed) with the same allele was obtained. The pattern of distribution of haplotypes was significantly different between patients and controls (p<0.0001), which is consistent with the role of the two functional variants of the promoter region.

CONCLUSION

In conclusion, our findings point to an association between functional variants in the promoter region of the HTR1B gene and alcohol dependence, supporting previous neurobiological evidences of the involvement of HTR1B variations in alcohol-related phenotypes.