Personality as an intermediate phenotype for genetic dissection of alcohol use disorder

Association Study of Serotonin 1A Receptor Gene, Personality, and Anxiety in Women with Alcohol Use Disorder

Alcohol use disorder is considered a chronic and relapsing disorder affecting the central nervous system. The serotonergic system, mainly through its influence on the mesolimbic dopaminergic reward system, has been postulated to play a pivotal role in the underlying mechanism of alcohol dependence. The study aims to analyse the association of the rs6295 polymorphism of the 5HTR1A gene in women with alcohol use disorder and the association of personality traits with the development of alcohol dependence, as well as the interaction of the rs6295, personality traits, and anxiety with alcohol dependence in women. The study group consisted of 213 female volunteers: 101 with alcohol use disorder and 112 controls. NEO Five-Factor and State-Trait Anxiety Inventories were applied for psychometric testing. Genotyping of rs6295 was performed by real-time PCR. We did not observe significant differences in 5HTR1A rs6295 genotypes (p = 0.2709) or allele distribution (p = 0.4513). The AUD subjects scored higher on the anxiety trait (p < 0.0001) and anxiety state (p < 0.0001) scales, as well as on the neuroticism (p < 0.0001) and openness (p = 0134) scales. Significantly lower scores were obtained by the AUD subjects on the extraversion (p < 0.0001), agreeability (p < 0.0001), and conscientiousness (p < 0.0001) scales. Additionally, we observed a significant effect of 5HTR1A rs6295 genotype interaction and alcohol dependency, or lack thereof, on the openness scale (p = 0.0016). In summary, this study offers a comprehensive overview of alcohol dependence among women. It offers valuable insights into this complex topic, contributing to a more nuanced understanding of substance use among this specific demographic. Additionally, these findings may have implications for developing prevention and intervention strategies tailored to individual genetic and, most importantly, personality and anxiety differences.

MAOA methylation is associated with impulsive and antisocial behaviour: dependence on allelic variation, family environment and diet

Congenital absence of monoamine oxidase A (MAO-A) activity predisposes to antisocial impulsive behaviour, and the MAOA uVNTR low-expressing genotype (MAOA-L) together with childhood maltreatment is associated with similar phenotypes in males. A possible explanation of how family environment may lead to such behaviour involves DNA methylation. We have assessed MAOA methylation and impulsive/antisocial behaviour in 121 males from the Estonian Children Personality Behaviour and Health Study. Of the 12 CpG sites measured, methylation levels at the locus designated CpG3 were significantly lower in subjects with antisocial behaviour involving police contact. CpG3 methylation was lower in subjects with alcohol use disorder by age 25, but only in MAOA-H genotype. No correlation between MAOA CpG3 methylation levels and adaptive impulsivity was found at age 15, but in MAOA-L genotype a positive correlation appeared by age 18. By age 25, this positive correlation was no longer observed in subjects with better family relationships but had increased further with experience of adversity within the family. MAOA CpG3 methylation had different developmental dynamics in relation to maladaptive impulsivity. At age 18, a positive correlation was observed in MAOA-L genotype with inferior family relationships and a negative correlation was found in MAOA-H with superior home environment; both of these associations had disappeared by age 25. CpG3 methylation was associated with dietary intake of several micronutrients, most notable was a negative correlation with the intake of zinc, but also with calcium, potassium and vitamin E; a positive correlation was found with intake of phosphorus. In conclusion, MAOA CpG3 methylation is related to both maladaptive and adaptive impulsivity in adolescence in MAOA-L males from adverse home environment. By young adulthood, this relationship with maladaptive impulsivity had disappeared but with adaptive impulsivity strengthened. Thus, MAOA CpG3 methylation may serve as a marker for adaptive developmental neuroplasticity in MAOA-L genotype. The mechanisms involved may include dietary factors.

An observational study on deliberate self-harm in individuals with alcohol dependence syndrome

Context

Comorbidities in alcohol dependence syndrome (ADS) are often associated with poor treatment outcomes and high service utilization. Deliberate self-harm (DSH) in India is a silent epidemic. There is a shortage of research on individuals with ADS, psychiatric comorbidities, and DSH.

Aim

To study DSH and psychiatric comorbidity in persons with ADS.

Settings and Design

A cross-sectional study of 1-year duration is conducted in out patient department/indoor patient department of a tertiary care hospital.

Methods and Material

Eighty-one individuals with ADS were selected purposefully. A semi-structured pro forma, the severity of alcohol dependence questionnaire, Mini-International Neuropsychiatric Interview (MINI), and Deliberate Self-Harm Inventory were administered for assessment. The statistical analysis used is as follows: correlation statistics and logistic regression.

Results

Most subjects were married, belonged to upper-middle socioeconomic status, had at least secondary education, and had moderate alcohol dependence severity. Almost 3/4th of the subjects had at least one lifetime psychiatric disorder. A past episode of major depressive disorder was found in 47%. Nearly 20% of study subjects had a history of DSH, which was significantly associated with unmarried status, and earlier age of alcohol dependence. Marital status, educational level, and age of onset of alcohol dependence explain 64.3% of the variance in DSH attempts. Suicidality was significantly related to the presence of DSH.

Conclusions

The study found a high prevalence of psychiatric disorders and a history of DSH in individuals with ADS. The study confirmed the association between DSH and suicidality and indicated a specific subpopulation of ADS who need thorough clinical assessments to recognize these psychiatric comorbidities and DSH.

Relationship of DRD5 and MAO-B VNTR polymorphisms with paranoid and antisocial personality disorders in polydrug users

Although multiple studies have shown the role genetics plays in personality disorders and in addictions, few have studied the genetic aspects of their comorbidity. Here, we carried out a cross-sectional study in a sample comprising 303 Caucasian polydrug-consuming patients. The presence of personality disorders was evaluated using the International Personality Disorder Examination, and genes related to dopamine, serotonin and monoamine oxidase (MAO) were genotyped. A significant relationship was observed between the bp 279 DRD5 variable number of tandem repeat (VNTR) polymorphism and paranoid personality disorder OR 95 % CI = 2.186 1.074 ; 4.449 ; p = 0.006 . The bp 182 OR 95 % CI = 0.407 0.178 ; 0.931 ; p = 0.033 and bp 184 OR 95 % CI = 0.391 0.188 ; 0.813 ; p = 0.012 alleles of the MAOB VNTR were also associated with antisocial personality disorder. Among patients with addictions, paranoid personality disorder should also be considered in addition to the importance of antisocial and borderline personality disorders. The higher frequency of the bp 279 DRD5 VNTR allele found in patients with paranoid personality disorder, as well as the associations between alleles of the MAOB VNTR and antisocial personality disorder, support the monoaminergic bases of these personality disorders, especially when dealing with patients with addictions.

Personality subtypes in adults with social anxiety disorder - novelty seeking makes the difference

BACKGROUND

Up to now several subtypes of social anxiety disorder (SAD) have been proposed.

METHODS

In the present study, we used a cluster analytic approach to identify qualitatively different subgroups of SAD based on temperament characteristics, that is, harm avoidance (HA) and novelty seeking (NS) dimensions of Cloninger's Temperament and Character Inventory.

RESULTS

Based on a large, diverse clinical sample (n = 575), we found evidence for two distinct subgroups of SAD: a larger (59%) prototypic, inhibited cluster characterized by high HA and low NS, and a smaller atypic, and comparatively more impulsive cluster characterized by medium to high HA and increased NS. The subgroups differed regarding a variety of sociodemographic and clinical variables. While the prototypic SAD subtype suffered from more severe SAD and depressive symptoms, suicidal ideation, and reduced social functioning, the atypic NS subtype showcased higher reproductive behaviour, self-directedness and -transcendence, comparatively. Additional hierarchical logistic regression highlights the contribution of age and education.

CONCLUSIONS

Our results valuably extend previous evidence for the existence of at least two distinct subtypes of SAD. A better knowledge of the characteristic differences in prototypic behaviour, personality, coping strategies and comorbidities between the identified (and further) subtypes can contribute to the development of effective prevention interventions and promotes the conceptualization of tailored treatments.

Psychiatric symptoms, current use of tobacco, alcohol, illicit drug, and poly-substance among medical students in Eastern Turkey

The study aims to investigate the prevalence and patterns of substance use among medical students and to examine associated psychiatric symptoms. It has been observed that depression and psychoticism scores have a significant effect on smoking, and interpersonal sensitivity-hostility-paranoid ideation scores have a significant effect on drinking. It has been shown that interpersonal sensitivity and depression scores are more predictive of mono-and poly-substance use. Revealing the relationship between tobacco, alcohol, poly-substance use, and psychiatric symptoms in the medical school sample shows the importance of practices aimed at increasing students' awareness of their psychiatric symptoms and providing access to psychiatric services.

Dual Diagnosis in Adolescents with Problematic Use of Video Games: Beyond Substances

The technological revolution has led to the birth of new diagnoses, such as gaming disorder. When any addiction, including this one, is associated with other mental disorders, it is considered a dual diagnosis. The objectives of this current work were to estimate the prevalence of dual diagnoses in the adolescent general population while also considering the problematic use of video games and substance addiction and assessing its psychosocial risk factors. Thus, we carried out a cross-sectional study with a sample of 397 adolescents; 16.4% presented problematic videogame use and 3% presented a dual diagnosis. Male gender increased the probability of both a dual diagnosis (OR [95% CI] = 7.119 [1.132, 44.785]; p = 0.036) and problematic video game use (OR [95% CI] = 9.85 [4.08, 23.77]; p < 0.001). Regarding personality, low conscientiousness, openness, and agreeableness scores were predictors of a dual diagnosis and problematic videogame use, while emotional stability predicted a dual diagnosis (OR [95% CI] = 1.116 [1.030, 1.209]; p = 0.008). Regarding family dynamics, low affection and communication increased both the probability of a dual diagnosis (OR [95% CI] = 0.927 [0.891, 0.965]; p < 0.001) and problematic video game use (OR [95% CI] = 0.968 [0.945, 0.992]; p = 0.009). Regarding academic performance, bad school grades increased the probability of a dual diagnosis. In summary, male gender, certain personality traits, poor communication, and poor affective family dynamics should be interpreted as red flags that indicate an increased risk of a dual diagnosis in adolescents, which could require early intervention through specific detection programs.

Do Individuals with Internet Gaming Disorder Share Personality Traits with Substance-Dependent Individuals?

(1) Background: Internet gaming disorder (IGD) shares many similarities with substance use disorder (SUD), contributing to its recognition as an addictive disorder. Nevertheless, no study has compared IGD to other addictive disorders in terms of personality traits established as highly co-occurring with SUDs. (2) Methods: We recruited a sample of gamers (massively multiplayer online role-playing games) (MMORPGs) via online in-game forums. We compared 83 individuals with IGD (MMORPG-IGD group) to 47 former heroin addicts under methadone maintenance treatment (MMT; MMT group) with regard to alexithymia, impulsivity, sensation seeking and aggressiveness assessed through self-administered scales, being TAS-20, BIS-10, Z-SSS and BDHI, respectively. (3) Results: Our results draw a relatively similar personality profile between groups but indicate that the subject traits are generally more pronounced in the MMT cohort. The overall lesser intensity of these traits in the MMORPG-IGD group might reflect the greater variability in the severity of the IGD. (4) Conclusions: IGD shares personality traits with MMT, and intensity may be influenced by the severity of the addiction or by certain direct environmental factors, and might also influence the propensity towards one behavior rather than another.

Serotonin Receptor HTR3A Gene Polymorphisms rs1985242 and rs1062613, E-Cigarette Use and Personality

We nowadays record growing numbers of e-cigarette users. The development of nicotine dependence is a result of many factors, including genetics and personality. In this study we analyzed two polymorphisms—rs1985242 and rs1062613—in the serotonin receptor HTR3A gene in a group of e-cigarette users (n = 135) and controls (n = 106). Personality traits were measured using the NEO Five-Factor Inventory. The comparison of e-cigarette users with the control group indicates that the former showed significantly higher scores on the neuroticism scale and lower scores on the scales of extraversion and conscientiousness of the NEO-FFI. Homozygote variants of rs1985242 were more frequent in the study group. The results of the 2 × 3 factorial ANOVA for e-cigarette users and the control group as well as interaction between the HTR3A rs1985242 variants were found for the NEO-FFI conscientiousness scale. These results allow us to conclude that the combination of psychological factors and genetic data creates a possibility for making more complete models of substance use disorders.

The cannabinoid receptor-1 gene interacts with stressful life events to increase the risk for problematic alcohol use

Problematic alcohol use is a major contributor to the global burden of death and disabilities, and it represents a public health concern that has grown substantially following the COVID-19 pandemic. The available treatment options remain limited and to develop better pharmacotherapies for alcohol misuse we need to identify suitable biological targets. Previous research has implicated the brain’s endocannabinoid system (ECS) in psychiatric and stress-related outcomes, including substance use and habituation to repeated stress. Moreover, genetic variants in the cannabinoid-1 receptor gene (CNR1; CB1R) have been associated with personality traits, which are in turn predictors of substance use disorders. To date, however, no human genome-wide association study has provided evidence for an involvement of the ECS in substance use outcomes. One reason for this ECS-related “missing heritability” may be unexamined gene-environment interactions. To explore this possibility, we conducted cross-sectional analyses using DNA samples and stress-exposure data from a longitudinal Swedish population-based study (N = 2,915). Specifically, we genotyped rs2023239, a functional C/T single nucleotide polymorphism in CNR1, previously reported to be associated with CNR1 binding in the brain, subjective reward following alcohol intake, and alcohol cue-elicited brain activation. Our two outcomes of interest were (i) problematic alcohol use based on the Alcohol Use Disorders Identification Test (AUDIT), and (ii) personality trait scores based on the Five Factor Model. We found no baseline association between rs2023239 and problematic alcohol use or personality traits. However, there was a clear trend for interaction between rs2023239’s risk allele (C) and stressful life events (SLEs) in both childhood and adulthood, which predicted problematic alcohol use. Although not significant, there was also some indication that the risk allele interacted with child SLEs to increase scores on neuroticism. Our study supports the notion that the ECS can affect alcohol intake behaviors by interacting with life adversities and is—to the best of our knowledge—the first to focus on the interaction between CNR1 and stressors in both childhood and adulthood in humans. Further studies are warranted to confirm these findings.

Association between platelet MAO activity and lifetime drug use in a longitudinal birth cohort study

RATIONALE

Platelet monoamine oxidase (MAO) activity, a marker of central serotonergic capacity, has been associated with a variety of problem behaviours. However, studies on platelet MAO activity and addictive drugs have not consistently linked MAO activity with addiction or reported to predict illicit substance use initiation or frequency.

OBJECTIVES

Platelet MAO activity and illicit drug use was examined in a longitudinal birth cohort study.

METHODS

The sample included both birth cohorts (original n = 1238) of the Estonian Children Personality Behaviour and Health Study. Longitudinal association from age 15 to 25 years between platelet MAO activity and lifetime drug use was analysed by mixed-effects regression models. Differences at ages 15, 18 and 25 were analysed by t-test. Cox proportional hazard regression analysis was used to assess the association between platelet MAO activity and the age of drug use initiation.

RESULTS

Male subjects who reported at least one drug use event had lower platelet MAO activity compared to nonusers, both in cross-sectional and longitudinal analyses. Males with low platelet MAO activity had started to use drugs at a younger age. Moreover, in male subjects who had experimented with illicit drugs only once in lifetime, low platelet MAO activity was also associated with higher risk at a younger age. In females, platelet MAO activity was not associated with drug use.

CONCLUSION

In males, low platelet MAO activity is associated with drug abuse primarily owing to risk-taking at early age.

Comprehensive meta-analysis of associations between temperament and character traits in Cloninger's psychobiological theory and mental disorders

OBJECTIVE

To explore the relationship between temperament and character traits in Cloninger's psychobiological theory and mental disorders.Methods: A systematic literature search was conducted of five international databases for all articles published in English between January 1990 and April 2019 (PROSPERO-CRD42019133214). Owing to heterogeneity, pooled estimates of correlations for personality disorders and standardized mean differences for case-control studies related to other mental disorders were calculated using the random-effects method.

RESULTS

The pooled effect sizes obtained from 149 studies showed that high harm avoidance (related to 22/24 diagnostic categories), low self-directedness (21/23), low cooperativeness (17/23), high self-transcendence (14/23), low reward dependence (11/24), high novelty-seeking (10/24), low novelty-seeking (7/24), high persistence (2/23), low persistence (2/23) and high reward dependence (2/24) were related to psychopathology.

CONCLUSIONS

All traits provided unique psychobiological tools for differential diagnosis of mental disorders. However, high harm avoidance and low self-directedness played a canonical role in psychopathology. Despite the study limitations, additional studies are warranted to evaluate the differential diagnoses suggested by the present model.

Personality-Related Factors and Depressive Symptomatology Predict Behavioral Control in Patients With Alcohol Use Disorders

In the face of increasing social, economic, and health consequences of alcohol use disorders (AUDs) and limited effects of available treatment options, the search for novel prevention and management methods continues to remain a timely and valid endeavor. This, however, requires a better grasp of the theoretical framework underlying addiction mechanisms. With the goal to extend the existing body of evidence on AUDs, we set out to investigate the effect of personality-related factors and depressive symptomatology on (i) impulsivity, (ii) cognitive response inhibition, and (iii) the links between the two measures of behavioral control (different facets of impulsivity and response inhibition) in a treatment-seeking AUD sample. To this end, 53 male (n = 45) and female (n = 8) inpatients at an alcohol rehabilitation center completed three self-report questionnaires: the International Personality Item Pool (IPIP-50), the Beck Depression Inventory Second Edition (BDI-II) and the Barratt Impulsiveness Scale (BIS-11) and performed one behavioral task-an alcohol go/no go task. Regression analyses revealed conscientiousness, intellect, and depression level to be important potential predictors of self-report impulsivity and processing speed in recovering drinkers. No significant links were observed between the two measures of behavioral control, thus complementing evidence that while they both encompass behavioral under-regulation, they may indeed represent distinct psychological constructs.

FACTORS CONTRIBUTING TO THE ESCALATION OF ALCOHOL CONSUMPTION

Understanding factors that contribute to the escalation of alcohol consumption is key to understanding how an individual transitions from non/social drinking to AUD and to providing better treatment. In this review, we discuss how the way ethanol is consumed as well as individual and environmental factors contribute to the escalation of ethanol consumption from intermittent low levels to consistently high levels. Moreover, we discuss how these factors are modelled in animals. It is clear a vast array of complex, interacting factors influence changes in alcohol consumption. Some of these factors act early in the acquisition of ethanol consumption and initial escalation, while others contribute to escalation of ethanol consumption at a later stage and are involved in the development of alcohol dependence. There is considerable need for more studies examining escalation associated with the formation of dependence and other hallmark features of AUD, especially studies examining mechanisms, as it is of considerable relevance to understanding and treating AUD.

Risk and resilience for alcohol use disorder revealed in brain functional connectivity

A family history of alcoholism (FH) increases risk for alcohol use disorder (AUD), yet many at-risk individuals never develop alcohol use problems. FH is associated with intermediate levels of risk phenotypes, whereas distinct, compensatory brain changes likely promote resilience. Although several cognitive, behavioral, and personality factors have been associated with AUD, the relative contributions of these processes and their neural underpinnings to risk or resilience processes remains less clear. We examined whole-brain resting-state functional connectivity (FC) and behavioral metrics from 841 young adults from the Human Connectome Project, including healthy controls, individuals with AUD, and their unaffected siblings. First, we identified functional connections in which unaffected siblings were intermediate between controls and AUD, indicating AUD risk, and those in which siblings diverged, indicating resilience. Canonical correlations relating brain risk and resilience FC to behavioral patterns revealed AUD risk and resilience phenotypes. Risk phenotypes primarily implicated frontal-parietal networks corresponding with executive function, impulsivity, externalizing behaviors, and social-emotional intelligence. Conversely, resilience-related phenotypes were underpinned by networks of medial prefrontal, striatal, temporal, brainstem and cerebellar connectivity, which associated with high trait attention and low antisocial behavior. Additionally, we calculated "polyphenotypic" risk and resilience scores, to investigate how the relative load of risk and resilience phenotypes influenced the probability of an AUD diagnosis. Polyphenotypic scores predicted AUD in a dose-dependent manner. Moreover, resilience phenotypes interacted with risk phenotypes, reducing their effects. The hypothesis-generating results revealed interpretable AUD-related phenotypes and offer brain-informed targets for developing more effective interventions.

Linking Big Five Personality Domains and Facets to Alcohol (Mis)Use: A Systematic Review and Meta-Analysis

AIMS

The goal of this investigation was to synthesize (un)published studies linking Big Five personality domains and facets to a range of alcohol use outcomes. Meta-analyses were conducted to quantify the unique associations between alcohol use outcomes and each Big Five personality domains over and above other domains. Within each domain, meta-analyses also were conducted to examine the unique contribution of each personality facet in predicting alcohol use outcomes.

METHODS

Systematic literature reviews were performed in PsycINFO and PubMed using keywords related to alcohol use and personality. Peer-reviewed and unpublished studies were screened and coded for the meta-analyses. A total of 80 independent samples were subjected to correlated effects meta-regressions.

RESULTS

Over and above other Big Five personality domains, both conscientiousness and agreeableness were negatively correlated with alcohol consumption, risky/hazardous drinking and negative drinking-related consequences. Facet-level analyses indicated that deliberation and dutifulness were uniquely associated with alcohol (mis)use over and above other conscientiousness facets, and compliance and straightforwardness were uniquely associated with alcohol (mis)use over and above other agreeableness facets. Extraversion-namely excitement seeking-was correlated with alcohol consumption, whereas neuroticism-namely impulsiveness and angry hostility-was correlated with negative drinking-related consequences.

CONCLUSIONS

Personality characteristics are robust correlates of alcohol (mis)use. Examining relevant narrowband traits can inform mechanisms by which personality affects drinking behaviors and related problems, and ways to enhance clinical interventions for alcohol use disorder. Gaps in this literature and future research directions are discussed.

Gender Difference in Longitudinal Social and Personal Factors Related to Frequency of Alcohol Consumption of South Korean Adults: A Fixed-Effects Model

The purpose of this study was to examine the longitudinal social and personal factors related to frequency of alcohol consumption by South Korean adults focused on comparisons between men and women. Data came from the 2005-2016 Korea Welfare Panel Study. A fixed-effects model was used to examine the longitudinal correlations between dependent and independent variables. According to the present results, first, life satisfaction except for health satisfaction and marital status were not associated with alcohol consumption patterns by men. On the other hand, higher frequency of alcohol consumption by women was negatively associated with various life satisfaction variables and being married. Second, income levels were positively associated with higher frequency of alcohol consumption by men, whereas income levels were not associated with alcohol consumption by women. Finally, being employed was positively associated with higher frequency of alcohol consumption by both men and women. In conclusion, there were gender differences in how alcohol consumption was influenced by various sociocultural and life satisfaction factors in South Korea.

Personality traits as predictors of early alcohol inebriation among young adolescents: Mediating effects by mental health and gender-specific patterns

The aim of this study was to predict alcohol inebriation and mental health (internalizing and externalizing problems plus well-being), and potential gender-specific patterns among young adolescents, by a biopsychosocial model of personality traits. Self-reported data from 853 adolescents (479 girls) in Sweden, aged 13-15 years, from the Longitudinal Research on Development In Adolescence (LoRDIA) program were used. Predictions from personality to inebriation and mediating effects of mental health were estimated by means of logistic regression and generalized structural equation modelling. Separated gender analyses were performed throughout the study to reveal potential gender-specific patterns. Externalizing problems, Novelty Seeking and Cooperativeness had independent effects on alcohol inebriation for both genders as well as Harm Avoidance among girls and Internalizing problems among boys. Novelty Seeking and Self-Directedness had indirect effects through externalizing problems and Harm Avoidance and Self-Directedness had indirect effects through internalizing problems for boys. Self-directedness showed an indirect effect through externalizing problems for girls. The combination of an immature character (low Self-directedness and Cooperativeness) with an extreme temperament profile (high Novelty Seeking and low Harm Avoidance) was a predictor of inebriation across gender, both directly and indirectly through mental health. This study contributes with valuable information about gender-specific considerations when developing and conducting preventative interventions targeting psychological risk and resilience factors for early alcohol inebriation among young adolescents.

Big Five personality traits and alcohol, nicotine, cannabis, and gambling disorder comorbidity

The Diagnostic and Statistical Manual of Mental Disorders (DSM; 5th ed.) reassignment of gambling disorder as an addictive disorder alongside the substance-related addictive disorders encourages research into their shared etiologies. The aims of this study were to examine: (a) the associations of Big Five personality dimensions with alcohol, nicotine, cannabis, and gambling disorders, (b) the comorbidity between these disorders, (c) the extent to which common personality underpinnings explain comorbidity, (d) whether results differed for men and women, and (e) the magnitude of personality differences corresponding to the 4 disorders. Participants were 3,785 twins and siblings (1,365 men, 2,420 women; M_age = 32 years, range = 21-46 years) from the Australian Twin Registry who completed psychiatric interviews and Big Five personality inventories. The personality profile of high neuroticism, low agreeableness, and low conscientiousness was associated with all 4 addictive disorders. All but 1 of the pairwise associations between the disorders were significant. After accounting for Big Five traits, the associations were attenuated to varying degrees but remained significant. The results were generally similar for men and women. The results suggest that the Big Five traits of neuroticism, agreeableness, and conscientiousness are associated with the general propensity to develop an addictive disorder and may in part explain their co-occurrence; however, they may be more broadly associated with the propensity for any psychiatric disorder. The effect sizes of the personality associations suggest that the diagnosis of gambling disorder as operationalized by the DSM may be more severe than the other addictive disorders. Calibration of the diagnosis of gambling disorder to the other addictive disorders may be warranted. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Biosignature Discovery for Substance Use Disorders Using Statistical Learning

There are limited biomarkers for substance use disorders (SUDs). Traditional statistical approaches are identifying simple biomarkers in large samples, but clinical use cases are still being established. High-throughput clinical, imaging, and 'omic' technologies are generating data from SUD studies and may lead to more sophisticated and clinically useful models. However, analytic strategies suited for high-dimensional data are not regularly used. We review strategies for identifying biomarkers and biosignatures from high-dimensional data types. Focusing on penalized regression and Bayesian approaches, we address how to leverage evidence from existing studies and knowledge bases, using nicotine metabolism as an example. We posit that big data and machine learning approaches will considerably advance SUD biomarker discovery. However, translation to clinical practice, will require integrated scientific efforts.

Associations Between MAOA-uVNTR Genotype, Maltreatment, MAOA Methylation, and Alcohol Consumption in Young Adult Males

BACKGROUND

Epigenetic mechanisms are candidate moderators of the effect of maltreatment on brain and behavior. Interactions between maltreatment and the monoamine oxidase A upstream variable number tandem repeat genotype (MAOA-uVNTR) are associated with alcohol-related problems. However, presently it is not known whether DNA methylation moderates this association. The study focused on 53 young adult males and aimed to determine whether MAOA methylation moderated the association of alcohol-related problems with the interaction of MAOA-uVNTR and maltreatment, and whether alcohol consumption moderated the association of MAOA methylation with the interaction of MAOA-uVNTR and maltreatment.

METHODS

MAOA-uVNTR genotypes with ≤ 3 and > 3 repeats were categorized as short (S) and long (L), respectively. Data on maltreatment were obtained retrospectively, using self-reported questionnaires. DNA methylation of 16 candidate CpGs within part of the MAOA first exon and intron was assessed and grouped based on principal component analyses. Alcohol-related problems were assessed using the Alcohol Use Disorders Identification Test (AUDIT). Alcohol consumption was measured using AUDIT-C. Moderation effects were assessed and probed using the moderated moderation model and Johnson-Neyman's method, respectively.

RESULTS

Carriers of the S allele, who experienced maltreatment and displayed lower Component 1 (mean of CpGs 13-16 in the first intron) MAOA methylation levels, reported higher AUDIT score in contrast to L-allele carriers. Carriers of the S allele, who reported higher AUDIT-C score and experienced maltreatment, displayed lower Component 3 (mean of CpGs 2-6 in the first exon) MAOA methylation levels than L-allele carriers.

CONCLUSIONS

Intronic methylation moderated the association of alcohol-related problems with the interaction of MAOA-uVNTR and maltreatment. Alcohol consumption moderated the association of exonic methylation with the interaction of MAOA-uVNTR and maltreatment. These results suggest that epigenetic factors as well as genotype and maltreatment play a role in the development of alcohol misuse among young adult males.

Cloninger's Temperament and Character Dimensions of Personality and Binge Drinking Among College Students

BACKGROUND

Temperament and character dimensions of personality remain largely unexplored in young adults exhibiting binge drinking (BD) patterns. Moreover, the available studies do not consider gender differences and dismiss possible personality heterogeneity among binge drinkers. In this study, we aimed to compare temperament and character dimensions between young binge drinkers and age- and sex-matched social drinkers. We further applied cluster analysis to investigate the potential heterogeneity of personality patterns among BD college students.

METHODS

This study included 200 university students of 18 to 24 years of age, who were recruited via an invitation to take an alcohol use survey. These participants included 100 individuals (50 females and 50 males) with a BD pattern, and 100 participants (50 females and 50 males) with a social drinking (SD) pattern. These subjects were evaluated with regard to their use of alcohol and other substances, impulsiveness, sensation seeking, mood, and Cloninger's Temperament and Character Inventory.

RESULTS

Between-group comparisons revealed that both male and female binge drinkers were characterized by high levels of novelty seeking, and low levels of persistence and self-directedness. However, cluster analyses within the binge drinker group revealed 2 distinct groups that differed between males and females. These groups shared similarities with Cloninger's type I (high harm-avoidance) and II (high novelty-seeking) alcoholism typology.

CONCLUSIONS

The present findings support the subdivision of binge drinkers according to gender and personality dimensions. Male and female binge drinkers should not be considered a unitary group, but rather a population of individuals that encompasses at least 2 distinct personality patterns. These findings have major implications for prevention and treatment approaches.

Personality Traits Related to Binge Drinking: A Systematic Review

The pattern of alcohol consumption in the form of binge drinking (BD) or heavy episodic drinking has increased notably worldwide in recent years, especially among adolescent and young people, being currently recognized as a global health problem. Although only a minority of binge drinkers will develop a substance use disorder, BD may have negative personal and social consequences in the short and medium term. The objective of this article is to review the findings on personality traits related to binge drinkers and to emphasize the aspects that should be examined in order to make progress in this area. The main characteristics of personality related to the practice of BD, regardless of the theoretical model used, are high Impulsivity and high Sensation seeking, as well as Anxiety sensitivity, Neuroticism (Hopelessness), Extraversion and low Conscientiousness. The data obtained may have theoretical implications to elucidate the endophenotype of BD, but they are especially useful for their preventive applications. Integration into prevention programs of emotional self-control skills, decision-making, social skills, and strategies to manage negative emotions will minimize the risk factors or consequences of BD associated with personality and will improve their effectiveness. In the future, it is necessary to harmonize a common measurement instrument for the assessment of personality, develop longitudinal studies with large samples that also integrate biological and neurocognitive measurements, and determine the reciprocal relationship between personality and BD together with its modulating variables, as well as the possible cultural differences.