ADH1A variation predisposes to personality traits and substance dependence

Emotional dysregulation, alexithymia and neuroticism: a systematic review on the genetic basis of a subset of psychological traits

Neuroticism, alexithymia and emotion dysregulation are key traits and known risk factors for several psychiatric conditions. In this systematic review, the aim is to evaluate the genetic contribution to these psychological phenotypes. A systematic review of articles found in PubMed was conducted. Search terms included 'genetic', 'GWAS', 'neuroticism', 'alexithymia' and 'emotion dysregulation'. Risk of bias was assessed utilizing the STREGA checklist. Two hundred two papers were selected from existing literature based on the inclusion and exclusion criteria. Among these, 27 were genome-wide studies and 175 were genetic association studies. Single gene association studies focused on selected groups of genes, mostly involved in neurotransmission, with conflicting results. GWAS studies on neuroticism, on the other hand, found several relevant and replicated intergenic and intronic loci affecting the expression and regulation of crucial and well-known genes (such as DRD2 and CRHR1). Mutations in genes coding for trascriptional factors were also found to be associated with neuroticism (DCC, XKR6, TCF4, RBFOX1), as well as a noncoding regulatory RNA (LINC00461). On the other hand, little GWAS data are available on alexythima and emotional dysregulation.

Comorbidity between depressive symptoms and substance use in-patients hospitalized for non-psychiatric diseases

INTRODUCTION

Epidemiological studies have shown a high prevalence and concurrence between depression and substance use. This is known as "dual diagnosis" and is associated with a worse prognosis for patients.

OBJECTIVE

To establish the comorbidity between depressive symptoms and substance abuse in patients admitted with acute or chronic diseases to a public hospital.

METHODS

A descriptive, cross-sectional study of prevalence which included 296 patients aged 18-65, to whom the PHQ-9 and ASSIST 3.0 scales were applied to determine the prevalence of depressive symptoms and substance abuse. Other clinical and sociodemographic variables were also taken into account.

RESULTS

50.7% were women with a median age of 41 and an interquartile range of 27 years. Moderate-to-severe depressive symptoms were found in 27.4% of the patients. Alcohol was the substance with the highest consumption in the previous 3 months with 53.7%, followed by cigarettes (47.6%), marijuana (26.7%) and cocaine (14.5%). A significant association was found between severe depressive symptoms PHQ-9 ≥ 20 and problematic use of alcohol, marijuana and cocaine (ASSIST score >26); alcohol (RP 27.30, 95% CI [2.37-314.16], P = 0.01); marijuana (RP 15.00, 95% CI [3.46-64.96], P = 0.001) and cocaine (RP 10.65, 95% CI [2.23-51.10], P = 0.01).

DISCUSSION

A high prevalence of depressive symptoms and substance use was found in patients hospitalised for non-psychiatric medical conditions, which worsens the prognosis of the underlying medical condition.

CONCLUSIONS

To provide better hospital care for patients, we need to give visibility to the problem of dual pathology. This could be achieved by conducting more related research in these clinical scenarios.

Comorbidity between depressive symptoms and substance use in-patients hospitalized for non-psychiatric diseases

INTRODUCTION

Epidemiological studies have shown a high prevalence and concurrence between depression and substance use. This is known as "dual diagnosis" and is associated with a worse prognosis for patients.

OBJECTIVE

To establish the comorbidity between depressive symptoms and substance abuse in patients admitted with acute or chronic diseases to a public hospital.

METHODS

A descriptive, cross-sectional study of prevalence which included 296 patients aged 18 to 65, to whom the PHQ-9 and ASSIST 3.0 scales were applied to determine the prevalence of depressive symptoms and substance abuse. Other clinical and sociodemographic variables were also taken into account.

RESULTS

50.7% were women with a median age of 41 and an interquartile range of 27 years. Moderate-to-severe depressive symptoms were found in 27.4% of the patients. Alcohol was the substance with the highest consumption in the previous 3 months with 53.7%, followed by cigarettes (47.6%), marijuana (26.7%) and cocaine (14.5%). A significant association was found between severe depressive symptoms PHQ-9 ≥20 and problematic use of alcohol, marijuana and cocaine (ASSIST score>26); alcohol (RP 27.30, 95% CI [2.37-314.16], P=0.01); marijuana (RP 15.00, 95% CI [3.46-64.96], P=0.001) and cocaine (RP 10.65, 95% CI [2.23-51.10], P=0.01).

DISCUSSION

A high prevalence of depressive symptoms and substance use was found in patients hospitalized for non-psychiatric medical conditions, which worsens the prognosis of the underlying medical condition.

CONCLUSIONS

To provide better hospital care for patients, we need to give visibility to the problem of dual pathology. This could be achieved by conducting more related research in these clinical scenarios.

The association between alcohol metabolism and genetic variants of ADH1A, SRPRB, and PGM1 in Korea

BACKGROUND

Excessive alcohol consumption is a major public health problem in East Asian countries. Alcohol use leads to a cascade of problems including increased chances of risky behavior and a wide range of negative health consequences, from alcoholic liver disease to upper gastric and liver cancer. These alcohol effects are known to be influenced by ethnic variability and genetics.

METHODS

In this study, subjects were administered a single dose of alcohol (0.6 g/kg for men or 0.4 g/kg for women), and blood alcohol and acetaldehyde concentrations were measured eight times over 5 hours. To investigate genetically susceptible factors to alcohol metabolism, we selected single-nucleotide polymorphisms (SNP) of genes identified by prior genetic association studies for alcohol metabolism, alcohol consumption, alcohol dependence, and related traits, and performed genotyping on all subjects (n = 104).

RESULTS

We identified variations in the ADH1A, SRPRB, and PGM1 genes, which are directly associated with blood alcohol or acetaldehyde concentrations. Namely, the T allele of SRPRB rs17376019 and the C allele of PGM1 rs4643 were associated with lower blood alcohol levels, while the ADH1 rs1229976 C allele group exhibited markedly higher blood acetaldehyde levels than those of the ADH1 rs1229976 T allele group.

CONCLUSION

This study demonstrates that genetic variations in ADH1A, SRPRB, and PGM1 are associated with variations in blood alcohol and acetaldehyde concentration after alcohol intake.

The ADH gene cluster SNP rs1789891 and temperamental dimensions in patients with alcohol dependence and affective disorders

This study had three objectives: (1) to assess the relationship between the single nucleotide polymorphism (SNP) rs1789891 in the alcohol dehydrogenase gene cluster and alcohol dependence and affective disorders; (2) to assess the differences in the Regulative Theory of Temperament (RTT) traits between an alcohol dependent group, an affective disorders group, and a healthy group; and (3) to assess the relationship between rs1789891 and temperament traits in a healthy group, taking into account the interaction of genotype and sex. The SNP rs1789891 was genotyped in a group of 194 alcohol dependent men, aged 21 to 71 years; 137 patients with affective disorders, including 51 males and 86 females, aged 19 to 85 years; and a group of 207 healthy individuals, including 89 males and 118 females, aged 18 to 71 years. Temperament traits (briskness, perseveration, sensory sensitivity, emotional reactivity, endurance, and activity) were assessed in all groups using the Formal Characteristics of Behaviour-Temperament Inventory. The comparative analysis of genotypic frequencies showed no significant differences between patients with alcoholism or affective disorders and those in the control group. Alcohol dependent men and the affective disorder group were characterised by higher levels of emotional reactivity (p-value 1.4e-5 and 9.84e-7, respectively) and lower levels of briskness, sensory sensitivity, endurance, and activity (p-value from 3.76e-8 to 0.012) when compared to the healthy group. The rs1789891 polymorphism was associated with briskness (p = 0.02), sensory sensitivity (p = 0.036), and activity (p = 0.049). None of the results were statistically significant after Bonferroni correction.

Use of diplotypes - matched haplotype pairs from homologous chromosomes - in gene-disease association studies

Alleles, genotypes and haplotypes (combinations of alleles) have been widely used in gene-disease association studies. More recently, association studies using diplotypes (haplotype pairs on homologous chromosomes) have become increasingly common. This article reviews the rationale of the four types of association analyses and discusses the situations in which diplotype-based analyses are more powerful than the other types of association analyses. Haplotype-based association analyses are more powerful than allele-based association analyses, and diplotype-based association analyses are more powerful than genotype-based analyses. In circumstances where there are no interaction effects between markers and where the criteria for Hardy-Weinberg Equilibrium (HWE) are met, the larger sample size and smaller degrees of freedom of allele-based and haplotype-based association analyses make them more powerful than genotype-based and diplotype-based association analyses, respectively. However, under certain circumstances diplotype-based analyses are more powerful than haplotype-based analysis.

Genetic strategies for probing conscientiousness and its relationship to aging

Conscientiousness is an important trait for understanding healthy aging. The present article addresses how behavioral and molecular genetics methodologies can aid in furthering explicating the link between conscientiousness and aspects of health and well-being in later life. We review the etiology of conscientiousness documented by both quantitative and molecular genetics methods. We also discuss the ways behavior genetics can be used to continue to help refine the concept of conscientiousness and to help identify points of etiological overlap between conscientiousness and healthy aging outcomes. Phenotypic research has established nontrivial associations between conscientiousness and important outcomes, but behavior genetic methods can determine what the causal (genetic and environmental) mechanisms are behind these relationships. An empirical example of one of these techniques is provided using twin data from the Midlife in the United States (MIDUS) study. We demonstrate that conscientiousness moderates genetic and environmental influences on problem alcohol use, such that greater levels of conscientiousness buffer against the random effects of the environment. Finally, suggestions for future work in this area are discussed.

Alcohol-medical drug interactions

Concomitant use of alcohol and medications may lead to potentially serious medical conditions. Increasing prescription medication abuse in today's society necessitates a deeper understanding of the mechanisms involved in alcohol-medication interactions in order to help prevent adverse events. Interactions of medications with alcohol result in altered bioavailability of the medication or alcohol (pharmacokinetic interactions) or modification of the effects at receptor or ion channel sites to alter behavioral or physical outcome (pharmacodynamic interactions). The nature of pharmacokinetic or pharmacodynamic interactions involved in alcohol-medication interactions may differ between acute and chronic alcohol use and be influenced by race, gender, or environmental or genetic factors. This review focuses on the mechanisms underlying pharmacokinetic and pharmacodynamic interactions between alcohol and medications and provides examples for such interactions from replicated research studies. In conclusion, further translational research is needed to address several gaps in our current knowledge of alcohol-medication interactions, including those under various pathologic conditions.

Association between common alcohol dehydrogenase gene (ADH) variants and schizophrenia and autism

Humans express at least seven alcohol dehydrogenase (ADH) isoforms that are encoded by ADH gene cluster (ADH7-ADH1C-ADH1B-ADH1A-ADH6-ADH4-ADH5) at chromosome 4. ADHs are key catabolic enzymes for retinol and ethanol. The functional ADH variants (mostly rare) have been implicated in alcoholism risk. In addition to catalyzing the oxidation of retinol and ethanol, ADHs may be involved in the metabolic pathways of several neurotransmitters that are implicated in the neurobiology of neuropsychiatric disorders. In the present study, we comprehensively examined the associations between common ADH variants [minor allele frequency (MAF) >0.05] and 11 neuropsychiatric and neurological disorders. A total of 50,063 subjects in 25 independent cohorts were analyzed. The entire ADH gene cluster was imputed across these 25 cohorts using the same reference panels. Association analyses were conducted, adjusting for multiple comparisons. We found 28 and 15 single nucleotide polymorphisms (SNPs), respectively, that were significantly associated with schizophrenia in African-Americans and autism in European-Americans after correction by false discovery rate (FDR) (q < 0.05); and 19 and 6 SNPs, respectively, that were significantly associated with these two disorders after region-wide correction by SNPSpD (8.9 × 10(-5) ≤ p ≤ 0.0003 and 2.4 × 10(-5) ≤ p ≤ 0.0003, respectively). No variants were significantly associated with the other nine neuropsychiatric disorders, including alcohol dependence. We concluded that common ADH variants conferred risk for both schizophrenia in African-Americans and autism in European-Americans.