Shared molecular genetic risk of alcohol dependence and posttraumatic stress disorder (PTSD)

Deciphering the shared genetic architecture between bipolar disorder and body mass index

BACKGROUND

The comorbidity between bipolar disorder (BD) and high body mass index (BMI) is well-documented, but their shared genetic architecture remains unclear. Our study aimed to explore this genetic correlation and potential causality.

METHODS

Utilizing large-scale genome-wide association study (GWAS) summary statistics, we quantified global and local genetic correlations between BD and BMI using linkage disequilibrium score regression (LDSC) and Heritability Estimation from Summary Statistics. Stratified LDSC characterized genetic overlap across functional categories. Cross-trait meta-analyses identified shared risk single nucleotide polymorphisms (SNPs), followed by colocalization analysis using Coloc. Bi-directional Mendelian randomization (MR) assessed causality, while tissue-level SNP heritability enrichment for BD and BMI was evaluated using LDSC-specific expressed genes and Multi-marker Analysis of Genomic Annotation.

RESULTS

We found a genetic correlation between BD and BMI, especially in localized genomic regions. Cross-trait meta-analysis identified 46 significant SNPs shared between BD and BMI, including three novel shared risk SNPs. Colocalization analysis verified two novel SNPs with shared causal variants linked to ITIH1 and TM6SF2 genes. MR analysis demonstrated a causal effect of BD on BMI, but not the reverse. Gene expression data revealed genetic correlation enrichment in five specific brain regions.

CONCLUSION

This study comprehensively analyzes the genetic correlation between BD and BMI, uncovering shared genetic architecture and identifying novel risk loci. These findings provide new insights into the interplay between BD and BMI, informing the development of diagnostic tools and therapeutic strategies.

What is the role of paternal genetic transmission on risk for PTSD and internalizing and externalizing disorders?

BACKGROUND

We utilize a novel contrastive genetic-epidemiological method, the Maternal Half-Sibling Families with Discordant Fathers (MHSFDF) design, to examine cross-generational genetic transmission of posttraumatic stress disorder (PTSD) and related internalizing major depression (MD), and externalizing disorders: alcohol use disorder (AUD) and drug use disorder (DUD).

METHODS

Using Swedish national registries, we identified 72,467 maternal half-sibling pairs reared together whose biological fathers were discordant for the diagnoses of PTSD, MD, AUD, and DUD. Offspring selected had to have less than 1 year of contact with their affected fathers. We examined the differences in outcome for within- and cross-disorder risk of diagnosis in the half-siblings with an affected versus unaffected father.

RESULTS

Paternal PTSD increased the risk of PTSD (HR: 1.43, 95% CI: 1.05-1.96) and MD (HR: 1.55, CI: 1.28-1.88) in offspring. It did not, however, elevate the risk of externalizing disorders (AUD or DUD). Offspring of fathers with AUD, DUD, or MD had increased risk of PTSD, suggesting sharing of vertically transmitted genetic risk between these disorders. No sex effects were found for any studied diagnosis.

CONCLUSIONS

This study is the first to show cross-generation genetic transmission for PTSD using the MHSFDF design. The pattern of cross-disorder genetic risk broadly supported an internalizing versus externalizing disorder split.

Advancing Mental Health Research Through Strategic Integration of Transdiagnostic Dimensions and Genomics

Genome-wide studies are yielding a growing catalog of common and rare variants that confer risk for psychopathology. However, despite representing unprecedented progress, emerging data also indicate that the full promise of psychiatric genetics-including understanding pathophysiology and improving personalized care-will not be fully realized by targeting traditional dichotomous diagnostic categories. The current article provides reflections on themes that emerged from a 2021 National Institute of Mental Health-sponsored conference convened to address strategies for the evolving field of psychiatric genetics. As anticipated by the National Institute of Mental Health's Research Domain Criteria framework, multilevel investigations of dimensional and transdiagnostic phenotypes, particularly when integrated with biobanks and big data, will be critical to advancing knowledge. The path forward will also require more diverse representation in source studies. Additionally, progress will be catalyzed by a range of converging approaches, including capitalizing on computational methods, pursuing biological insights, working within a developmental framework, and engaging health care systems and patient communities.

Pharmacological treatments for co-occurring PTSD and substance use disorders: A systematic review

INTRODUCTION

Post-traumatic stress disorder and substance use disorders commonly co-occur and are associated with worse health outcomes. Currently, only psychosocial therapies are specifically recommended for use in the co-occurring population, but these come with numerous barriers to access and engagement. This study aims to identify potential pharmacological treatments to enhance treatment options and outcomes for this population.

METHODS

This systematic review identified studies on pharmacological treatment of co-occurring PTSD and SUD in humans, using validated outcome measurements, with study design of RCT, observational study, case control study or cohort study.

RESULTS

29 studies were identified for inclusion, looking at a range of 16 pharmacotherapies. A majority concentrated on alcohol use disorders and males, with many focused on the veteran population.

CONCLUSIONS

This is an area for further research, inclusive of more SUDs, genders and civilians. Future studies utilizing consistent dosing, populations and measurement outcomes will allow for future meta-analysis.

Genetic basis and causal relationship between atrial fibrillation and sinus node dysfunction: Evidence from comprehensive genetic analysis

BACKGROUND

Atrial fibrillation (AF) and sinus node dysfunction (SND) are commonly observed together clinically. However, little is known about the genetic background and causal relationship between the two.

METHODS

Firstly, we investigated the global and local genetic correlations between AF and SND using LDSC and HESS. Then, we identified shared "Novel SNPs" between AF and SND through two complementary cross-trait meta-analyses and mapped the "pleiotropic genes" behind these SNPs, validated by colocalization analysis. Additionally, we explored the degree of genetic enrichment of SNPs in specific tissues using LDSC-SEG and MAGMA, and identified potential functional genes in tissues using summary data-based Mendelian randomization (SMR). Finally, two-sample Mendelian randomization (TSMR) and multivariable Mendelian randomization (MVMR) were used to explore the causal relationship between AF and SND.

RESULTS

Both global and local genetic correlation analyses revealed a high positive genetic correlation between AF and SND. HESS identified 9 shared loci, with chr4(q25-q26) and chr11(p11.12-q11) being prominent. Cross-trait meta-analysis and colocalization analysis identified ENPEP and PITX2 as novel pleiotropic genes. MAGMA revealed genetic enrichment of SNPs for AF and SND in the "Heart Left Ventricle" and "Heart Atrial Appendage" tissues, with CEP68 and BEST3 identified as potential functional genes through SMR. MR analysis indicated that AF increases the risk of SND, even after adjusting for confounding factors.

CONCLUSION

This study provides genetic evidence for the increased risk of SND associated with AF, identifying multiple shared risk loci and enriched tissues, and discovering 2 novel pleiotropic genes and 2 new functional genes.

Disentangling the genetic overlap between ischemic stroke and obesity

OBJECTIVE

Obesity has been recognized as a risk factor for cerebrovascular diseases, with observational studies suggesting a heightened incidence of stroke. However, the genetic epidemiology field has yet to reach a consensus on the causal relationship and genetic overlap between ischemic stroke (IS) and obesity.

METHODS

We utilized linkage disequilibrium score regression, high-definition likelihood, and local analysis of variant associations to assess the genetic correlation between body mass index (BMI) and IS. Bidirectional Mendelian randomization was employed to infer causality. We identified shared risk single nucleotide polymorphisms (SNPs) through cross-trait meta-analyses and estimated heritability using summary statistics. Summary-data-based Mendelian randomization (SMR) was applied to explore potential functional genes.

RESULTS

Our analysis revealed a significant positive genetic correlation between BMI and IS, supporting a causal link from BMI to IS. Cross-trait analysis yielded 9 and 16 shared risk SNPs for IS and small vessel stroke (SVS), respectively. We observed a notable enrichment of SNP heritability for IS and BMI in brain tissues, suggesting tissue-specific influences. The genes shared between the traits were predominantly involved in brain development, synaptic electrical activity, and immunoregulation. Notably, our SMR analysis identified the risk genes CHAF1A, CEP192, ULK4, CYP2D6, AS3MT, and WARS2 across the majority of the 14 enriched tissues shared by both traits.

CONCLUSION

Our study uncovered a significant genetic correlation and identified shared risk SNPs between BMI and IS. The identification of CHAF1A, CEP192, ULK4, CYP2D6, AS3MT, and WARS2 as potential functional genes common to both obesity and IS enriched our understanding of their genetic interplay, potentially advanced our grasp of their pathogenesis and therapeutic targets.

Posttraumatic stress disorder and its cross-generational familial relationship with drug use disorder and alcohol use disorder: an extended Swedish adoption study

Objective: Information on how parental risk for posttraumatic stress disorder (PTSD) relates to their children's risk for drug use disorder (DUD) and alcohol use disorder (AUD) is limited. This study is the first to utilize an extended adoption design which can address questions about the degree of, and sources of, cross-generational and cross-disorder transmission of PTSD and substance use disorders.Method: We examined diagnoses using Swedish National registries for parents and their adult offspring (n = 2,194,171, born 1960-1992) from six types of families (intact (1), not lived with biological father (2) or mother (3), step father (4), step mother (5), and adoptive (6)). Parent-child resemblance was assessed by tetrachoric correlation.Results: PTSD and DUD showed an approximately symmetrical cross-generational cross-disorder relationship. Conversely, AUD in parents was more related to the risk for PTSD in offspring compared to the reverse direction. The cross-disorder cross-generation transmission correlations for PTSD to DUD were higher than those for PTSD to AUD. Genetic and rearing correlations for PTSD-DUD were estimated at + .79 (CI: .66, .91) and + .49 (CI: .33, .65), significantly higher than those for PTSD-AUD + .59 (CI: .48, .71) and + .28 (CI: .12, .44).Conclusions: PTSD and the substance use disorders demonstrated cross-transmission, but more so for DUD. PTSD and DUD demonstrated highly correlated genetic effects, and moderately correlated rearing effects. Correlations of genetic and rearing effects between PTSD and AUD were lower than those for PTSD and DUD.

Integrating Drug Target Information in Deep Learning Models to Predict the Risk of Adverse Events in Patients with Comorbid Post-Traumatic Stress Disorder and Alcohol Use Disorder

Background/Objectives: Comorbid post-traumatic stress disorder (PTSD) and alcohol use disorder (AUD) patients are at a significantly higher risk of adverse outcomes, including opioid use disorder, depression, suicidal behaviors, and death, yet limited treatment options exist for this population. This study aimed to build on previous research by incorporating drug target information into a novel deep learning model, T-DeepBiomarker, to predict adverse outcomes and identify potential therapeutic medications. Methods: We utilized electronic medical record (EMR) data from the University of Pittsburgh Medical Center (UPMC), analyzing 5565 PTSD + AUD patients. T-DeepBiomarker was developed by integrating multimodal data, including lab results, drug target information, comorbidities, neighborhood-level social determinants of health (SDoH), and individual-level SDoH (e.g., psychotherapy and veteran status). The model was trained to predict adverse events, including opioid use disorder, suicidal behaviors, depression, and death, within three months following any clinical encounter. Candidate medications targeting significant proteins were identified through literature reviews. Results: T-DeepBiomarker achieved high predictive performance with an AUROC of 0.94 for adverse outcomes in PTSD + AUD patients. Several medications, including OnabotulinumtoxinA, Dronabinol, Acamprosate, Celecoxib, Exenatide, Melatonin, and Semaglutide, were identified as potentially reducing the risk of adverse events by targeting significant proteins. Conclusions: T-DeepBiomarker demonstrates high accuracy in predicting adverse outcomes in PTSD + AUD patients and highlights candidate drugs with potential therapeutic effects. These findings advance pharmacotherapy for this high-risk population and identify medications that warrant further investigation.

Childhood trauma is associated with developmental trajectories of EEG coherence, alcohol-related outcomes, and PTSD symptoms

BACKGROUND

Associations between childhood trauma, neurodevelopment, alcohol use disorder (AUD), and posttraumatic stress disorder (PTSD) are understudied during adolescence.

METHODS

Using 1652 participants (51.75% female, baseline Mage = 14.3) from the Collaborative Study of the Genetics of Alcoholism, we employed latent growth curve models to (1) examine associations of childhood physical, sexual, and non-assaultive trauma (CPAT, CSAT, and CNAT) with repeated measures of alpha band EEG coherence (EEGc), and (2) assess whether EEGc trajectories were associated with AUD and PTSD symptoms. Sex-specific models accommodated sex differences in trauma exposure, AUD prevalence, and neural development.

RESULTS

In females, CSAT was associated with higher mean levels of EEGc in left frontocentral (LFC, ß = 0.13, p = 0.01) and interhemispheric prefrontal (PFI, ß = 0.16, p < 0.01) regions, but diminished growth in LFC (ß = -0.07, p = 0.02) and PFI (ß = -0.07, p = 0.02). In males, CPAT was associated with lower mean levels (ß = -0.17, p = 0.01) and increased growth (ß = 0.11, p = 0.01) of LFC EEGc. Slope of LFC EEGc was inversely associated with AUD symptoms in females (ß = -1.81, p = 0.01). Intercept of right frontocentral and PFI EEGc were associated with AUD symptoms in males, but in opposite directions. Significant associations between EEGc and PTSD symptoms were also observed in trauma-exposed individuals.

CONCLUSIONS

Childhood assaultive trauma is associated with changes in frontal alpha EEGc and subsequent AUD and PTSD symptoms, though patterns differ by sex and trauma type. EEGc findings may inform emerging treatments for PTSD and AUD.

Assessing shared psychological constructs as risk factors in comorbid PTSD-AUD combat-exposed male veterans

PTSD and AUD are frequently comorbid post-trauma outcomes. Much remains unknown about shared risk factors as PTSD and AUD work tends to be conducted in isolation. We examined how self-report measures of distress tolerance (DT), experiential avoidance (EA), and drinking motives (DM) differed across diagnostic groups in white, male combat-exposed veterans (n = 77). A MANOVA indicated a significant difference in constructs by group, F (5, 210) = 4.7, p = <.001. Follow-up ANOVAs indicated DM subscales (Coping: F (3,82) = 21.3; Social: F (3,82) = 13.1; Enhancement: F (3,82) = 10.4; ps = <.001) and EA (F (3,73) = 7.8, p < .001) differed by groups but not DT. Post hoc comparisons indicated that mean scores of the comorbid and AUD-only groups were significantly higher than controls for all DM subscales (all ps < .01). EA scores were significantly higher for the comorbid as compared to control (p < .001) and PTS-only (p = .007) groups. Findings support shared psychological factors in a comorbid PTSD-AUD population.

Genetic correlation between smoking behavior and gastroesophageal reflux disease: insights from integrative multi-omics data

BACKGROUND

Observational studies have preliminarily revealed an association between smoking and gastroesophageal reflux disease (GERD). However, little is known about the causal relationship and shared genetic architecture between the two. This study aims to explore their common genetic correlations by leveraging genome-wide association studies (GWAS) of smoking behavior-specifically, smoking initiation (SI), never smoking (NS), ever smoking (ES), cigarettes smoked per day (CPD), age of smoking initiation(ASI) and GERD.

METHODS

Firstly, we conducted global cross-trait genetic correlation analysis and heritability estimation from summary statistics (HESS) to explore the genetic correlation between smoking behavior and GERD. Then, a joint cross-trait meta-analysis was performed to identify shared "pleiotropic SNPs" between smoking behavior and GERD, followed by co-localization analysis. Additionally, multi-marker analyses using annotation (MAGMA) were employed to explore the degree of enrichment of single nucleotide polymorphism (SNP) heritability in specific tissues, and summary data-based Mendelian randomization (SMR) was further utilized to investigate potential functional genes. Finally, Mendelian randomization (MR) analysis was conducted to explore the causal relationship between the smoking behavior and GERD.

RESULTS

Consistent genetic correlations were observed through global and local genetic correlation analyses, wherein SI, ES, and CPD showed significantly positive genetic correlations with GERD, while NS and ASI showed significantly negative correlations. HESS analysis also identified multiple significantly associated loci between them. Furthermore, three novel "pleiotropic SNPs" (rs4382592, rs200968, rs1510719) were identified through cross-trait meta-analysis and co-localization analysis to exist between SI, NS, ES, ASI, and GERD, mapping the genes MED27, HIST1H2BO, MAML3 as new pleiotropic genes between SI, NS, ES, ASI, and GERD. Moreover, both smoking behavior and GERD were found to be co-enriched in multiple brain tissues, with GMPPB, RNF123, and RBM6 identified as potential functional genes co-enriched in Cerebellar Hemisphere, Cerebellum, Cortex/Nucleus accumbens in SI and GERD, and SUOX identified in Caudate nucleus, Cerebellum, Cortex in NS and GERD. Lastly, consistent causal relationships were found through MR analysis, indicating that SI, ES, and CPD increase the risk of GERD, while NS and higher ASI decrease the risk.

CONCLUSION

We identified genetic loci associated with smoking behavior and GERD, as well as brain tissue sites of shared enrichment, prioritizing three new pleiotropic genes and four new functional genes. Finally, the causal relationship between smoking behavior and GERD was demonstrated, providing insights for early prevention strategies for GERD.

Line- and sex-dependent effects of juvenile stress on contextual fear- and anxiety-related behavior in high- and low-alcohol-preferring mouse lines

Juvenile stress (JS) is a known risk factor for the development of alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD), both of which are frequently co-morbid. Data suggest there may be common, genetically-influenced biological responses to stress that contribute to the development of both AUD and PTSD. The present study investigated the impact of JS on contextual fear learning and extinction, as well as corticosterone (CORT) responses before and after JS, before and after contextual fear conditioning (CFC), and after fear extinction in male and female high-alcohol-preferring (HAP2) and low-alcohol-preferring (LAP2) mouse lines. We also measured unconditioned anxiety-related behavior in the light-dark-transition test before CFC. HAP2 and LAP2 mice did not differ in fear acquisition, but HAP2 mice showed faster fear extinction compared to LAP2 mice. No effects of JS were seen in HAP2 mice, whereas in LAP2 mice, JS reduced fear acquisition in males and facilitated fear extinction in females. Females showed greater fear-related behavior relative to males, regardless of subgroup. HAP2 males demonstrated more anxiolytic-like responses than LAP2 males and LAP2 females demonstrated more anxiolytic-like responses than LAP2 males in the light-dark transition test. HAP2 and LAP2 mice did not differ in CORT during the juvenile stage; however, adult LAP2 mice showed greater CORT levels than HAP2 mice at baseline and after CFC and extinction testing. These findings build upon prior work in these unique mouse lines that differ in genetic propensity toward alcohol preference and provide new information regarding contextual fear learning and extinction mechanisms theorized to contribute to co-morbid AUD and PTSD.

Sex and Gender Differences in Co-Occurring Alcohol Use Disorder and PTSD

Purpose of Review

Research demonstrates a strong association between alcohol use disorder (AUD) and posttraumatic stress disorder (PTSD). However, less is known about sex- and gender-based differences among individuals with AUD + PTSD. This narrative review examines recent literature in this area and aims to be a reference for future research endeavors.

Recent Findings

Extant literature shows that intertwining biological systems increase females' risk of developing PTSD and experiencing more adverse effects from AUD compared to males. Sex-based physiological differences further interact with gendered sociocultural environments to influence the risk of AUD + PTSD. Emerging research suggests potential gender-specific pathways between PTSD, coping, and AUD which may inform prevention and treatment. However, barriers to care are often gender-specific and tailored approaches are needed to improve reach and uptake.

Summary

Additional research is needed to examine intersectional and contextual factors that synergistically influence sex/gender differences in AUD + PTSD, particularly beyond cisgender identities, and mechanisms of action.

Differences in genetic correlations between posttraumatic stress disorder and alcohol-related problems phenotypes compared to alcohol consumption-related phenotypes

BACKGROUND

Posttraumatic Stress Disorder (PTSD) tends to co-occur with greater alcohol consumption as well as alcohol use disorder (AUD). However, it is unknown whether the same etiologic factors that underlie PTSD-alcohol-related problems comorbidity also contribute to PTSD- alcohol consumption.

METHODS

We used summary statistics from large-scale genome-wide association studies (GWAS) of European-ancestry (EA) and African-ancestry (AA) participants to estimate genetic correlations between PTSD and a range of alcohol consumption-related and alcohol-related problems phenotypes.

RESULTS

In EAs, there were positive genetic correlations between PTSD phenotypes and alcohol-related problems phenotypes (e.g. Alcohol Use Disorders Identification Test (AUDIT) problem score) (rGs: 0.132-0.533, all FDR adjusted p < 0.05). However, the genetic correlations between PTSD phenotypes and alcohol consumption -related phenotypes (e.g. drinks per week) were negatively associated or non-significant (rGs: -0.417 to -0.042, FDR adjusted p: <0.05-NS). For AAs, the direction of correlations was sometimes consistent and sometimes inconsistent with that in EAs, and the ranges were larger (rGs for alcohol-related problems: -0.275 to 0.266, FDR adjusted p: NS, alcohol consumption-related: 0.145-0.699, FDR adjusted p: NS).

CONCLUSIONS

These findings illustrate that the genetic associations between consumption and problem alcohol phenotypes and PTSD differ in both strength and direction. Thus, the genetic factors that may lead someone to develop PTSD and high levels of alcohol consumption are not the same as those that lead someone to develop PTSD and alcohol-related problems. Discussion around needing improved methods to better estimate heritabilities and genetic correlations in diverse and admixed ancestry samples is provided.

Genetic associations between alcohol phenotypes and life satisfaction: a genomic structural equation modelling approach

Alcohol use (i.e., quantity, frequency) and alcohol use disorder (AUD) are common, associated with adverse outcomes, and genetically-influenced. Genome-wide association studies (GWAS) identified genetic loci associated with both. AUD is positively genetically associated with psychopathology, while alcohol use (e.g., drinks per week) is negatively associated or NS related to psychopathology. We wanted to test if these genetic associations extended to life satisfaction, as there is an interest in understanding the associations between psychopathology-related traits and constructs that are not just the absence of psychopathology, but positive outcomes (e.g., well-being variables). Thus, we used Genomic Structural Equation Modeling (gSEM) to analyze summary-level genomic data (i.e., effects of genetic variants on constructs of interest) from large-scale GWAS of European ancestry individuals. Results suggest that the best-fitting model is a Bifactor Model, in which unique alcohol use, unique AUD, and common alcohol factors are extracted. The genetic correlation (rg) between life satisfaction-AUD specific factor was near zero, the rg with the alcohol use specific factor was positive and significant, and the rg with the common alcohol factor was negative and significant. Findings indicate that life satisfaction shares genetic etiology with typical alcohol use and life dissatisfaction shares genetic etiology with heavy alcohol use.

Genomic risk for post-traumatic stress disorder in families densely affected with alcohol use disorders

Recent genome-wide association studies (GWAS) have identified genetic markers of post-traumatic stress disorder (PTSD) in civilian and military populations. However, studies have yet to examine the genetics of PTSD while factoring in risk for alcohol dependence, which commonly co-occur. We examined genome-wide associations for DSM-IV PTSD among 4,978 trauma-exposed participants (31% with alcohol dependence, 50% female, 30% African ancestry) from the Collaborative Study on the Genetics of Alcoholism (COGA). We also examined associations of polygenic risk scores (PRS) derived from the Psychiatric Genomics Consortium (PGC)-PTSD Freeze 2 (N = 3533) and Million Veterans Program GWAS of PTSD (N = 5200) with PTSD and substance dependence in COGA, and moderating effects of sex and alcohol dependence. 7.3% of COGA participants met criteria for PTSD, with higher rates in females (10.1%) and those with alcohol dependence (12.3%). No independent loci met genome-wide significance in the PTSD meta-analysis of European (EA) and African ancestry (AA) participants. The PGC-PTSD PRS was associated with increased risk for PTSD (B = 0.126, p < 0.001), alcohol dependence (B = 0.231, p < 0.001), and cocaine dependence (B = 0.086, p < 0.01) in EA individuals. A significant interaction was observed, such that EA individuals with alcohol dependence and higher polygenic risk for PTSD were more likely to have PTSD (B = 0.090, p < 0.01) than those without alcohol dependence. These results further support the importance of examining substance dependence, specifically alcohol dependence, and PTSD together when investigating genetic influence on these disorders.

Investigating the shared genetic architecture between schizophrenia and body mass index

Evidence for reciprocal comorbidity of schizophrenia (SCZ) and body mass index (BMI) has grown in recent years. However, little is known regarding the shared genetic architecture or causality underlying the phenotypic association between SCZ and BMI. Leveraging summary statistics from the hitherto largest genome-wide association study (GWAS) on each trait, we investigated the genetic overlap and causal associations of SCZ with BMI. Our study demonstrated a genetic correlation between SCZ and BMI, and the correlation was more evident in local genomic regions. The cross-trait meta-analysis identified 27 significant SNPs shared between SCZ and BMI, most of which had the same direction of influence on both diseases. Mendelian randomization analysis showed the causal association of SCZ with BMI, but not vice versa. Combining the gene expression information, we found that the genetic correlation between SCZ and BMI is enriched in six regions of brain, led by the brain frontal cortex. Additionally, 34 functional genes and 18 specific cell types were found to have an impact on both SCZ and BMI within these regions. Taken together, our comprehensive genome-wide cross-trait analysis suggests a shared genetic basis including pleiotropic loci, tissue enrichment, and shared function genes between SCZ and BMI. This work provides novel insights into the intrinsic genetic overlap of SCZ and BMI, and highlights new opportunities and avenues for future investigation.

Phenome-wide Association Analysis of Substance Use Disorders in a Deeply Phenotyped Sample

BACKGROUND

Substance use disorders (SUDs) are associated with a variety of co-occurring psychiatric disorders and other SUDs, which partly reflects genetic pleiotropy. Polygenic risk scores (PRSs) and phenome-wide association studies are useful in evaluating pleiotropic effects. However, the comparatively low prevalence of SUDs in population samples and the lack of detailed information available in electronic health records limit these data sets' informativeness for such analyses.

METHODS

We used the deeply phenotyped Yale-Penn sample (n = 10,610 with genetic data; 46.3% African ancestry, 53.7% European ancestry) to examine pleiotropy for 4 major substance-related traits: alcohol use disorder, opioid use disorder, smoking initiation, and lifetime cannabis use. The sample includes both affected and control subjects interviewed using the Semi-Structured Assessment for Drug Dependence and Alcoholism, a comprehensive psychiatric interview.

RESULTS

In African ancestry individuals, PRS for alcohol use disorder, and in European individuals, PRS for alcohol use disorder, opioid use disorder, and smoking initiation were associated with their respective primary DSM diagnoses. These PRSs were also associated with additional phenotypes involving the same substance. Phenome-wide association study analyses of PRS in European individuals identified associations across multiple phenotypic domains, including phenotypes not commonly assessed in phenome-wide association study analyses, such as family environment and early childhood experiences.

CONCLUSIONS

Smaller, deeply phenotyped samples can complement large biobank genetic studies with limited phenotyping by providing greater phenotypic granularity. These efforts allow associations to be identified between specific features of disorders and genetic liability for SUDs, which help to inform our understanding of the pleiotropic pathways underlying them.

Prenatal alcohol exposure enhanced alcohol preference and susceptibility to PTSD in a sex-dependent manner through the synaptic HCN1 channel

BACKGROUND

Prenatal alcohol exposure (PAE) adversely affects the neurobiological and behavioral functions of offspring. Increasing evidence indicates that alcohol-use disorders and post-traumatic stress disorder (PTSD) commonly co-occur. Enhanced function of hyperpolarization-activated gated channel 1 (HCN1) may be involved in the pathogenesis of PTSD. This study aimed to explore the effect of PAE on fear extinction, spontaneous recovery, alcohol preference, and function of HCN1 channels in offspring of both sexes.

METHODS

The PAE model was established with a 20 % (m/V) ethanol solution, and offspring were treated with 0.5, 1, and 2 μg/mL ZD7288 to block the HCN1 channel. Behavioral tests were used to detect the mental state and fear of extinction of the mice. Western blot was used to detect HCN1 expression in the synaptosomes. The BDNF/TrkB-pmTOR pathway was also examined.

RESULTS

ZD7288 administration ameliorated PAE-induced impairment of fear extinction and depression-like behavior. ZD7288 administration also alleviated PAE-induced inhibition of the HCN1 channel in the prefrontal cortex (PFC) and the BDNF/TrkB-pmTOR pathway in the hippocampus of offspring. In addition, the therapeutic effect of ZD7288 in males was better than that in females.

CONCLUSIONS

Overall, these results suggest that PAE enhances alcohol preference and susceptibility to PTSD through synaptic HCN1 channels in the PFC. In addition, ZD7288 may be a promising candidate for preventing alcohol-associated PTSD-like syndrome, particularly in males.

LIMITATIONS

The effects of ZD7288 were only studied in PAE animals and not in healthy animals.

Genetic Addiction Risk and Psychological Profiling Analyses for "Preaddiction" Severity Index

Since 1990, when our laboratory published the association of the DRD2 Taq A1 allele and severe alcoholism in JAMA, there has been an explosion of genetic candidate association studies, including genome-wide association studies (GWAS). To develop an accurate test to help identify those at risk for at least alcohol use disorder (AUD), a subset of reward deficiency syndrome (RDS), Blum's group developed the genetic addiction risk severity (GARS) test, consisting of ten genes and eleven associated risk alleles. In order to statistically validate the selection of these risk alleles measured by GARS, we applied strict analysis to studies that investigated the association of each polymorphism with AUD or AUD-related conditions, including pain and even bariatric surgery, as a predictor of severe vulnerability to unwanted addictive behaviors, published since 1990 until now. This analysis calculated the Hardy-Weinberg Equilibrium of each polymorphism in cases and controls. Pearson's χ2 test or Fisher's exact test was applied to compare the gender, genotype, and allele distribution if available. The statistical analyses found the OR, 95% CI for OR, and the post risk for 8% estimation of the population's alcoholism prevalence revealed a significant detection. Prior to these results, the United States and European patents on a ten gene panel and eleven risk alleles have been issued. In the face of the new construct of the "preaddiction" model, similar to "prediabetes", the genetic addiction risk analysis might provide one solution missing in the treatment and prevention of the neurological disorder known as RDS.

Group cognitive behavioral therapy as an effective approach for patients with alcohol dependence: A perspective study

Alcohol dependence (AD) syndrome refers to a strong addiction to alcohol and high tolerance physiologically or psychologically, due to the repeated consumption of alcohol-based substances. This study aimed to examine the efficacy of group cognitive behavioral therapy (GCBT) on patients with AD. A total of 128 patients with AD were randomly assigned to the GCBT or control group. Patients in the GCBT group underwent an 8-week GCBT in addition to conventional treatment, and patients in the control group only received conventional treatment. The insight and treatment attitude questionnaire (ITAQ) score, chronic disease self-cognition evaluation score (CDSCES), treatment adherence, and relapse rate at 6 and 12 months were compared among the 2 groups. The ITAQ scores of the GCBT group, after treatment, increased significantly compared to those of the control group (19.69% vs 13.26%, P < .001). The CDSCES in the GCBT group increased significantly compared to those in the control group after treatment (3.98 vs 2.18, P = .001 for problem-solving ability; 8.08 vs 5.08, P = .001 for self-management efficacy; 4.29 vs 3.30, P = .005 for a positive response, and 4.84 vs 3.44, P = .008 for a social function, respectively). After treatment, the percentage of patients with AD with full compliance in the GCBT group was much higher than in the control group (93.8% vs 65.6%, P < .001). Contrastingly, the percentage of patients with AD with partial compliance in the GCBT group was much lower than that in the control group (3.2% vs 34.4%, P < .001). The relapse rate (%) of drinking in patients with AD in the GCBT group was much lower than that in the control group (1.56% vs 21.8%, P = .001 for 6 months and 4.7% vs 51.6%, P < .001 for 12 months). The results suggest that GCBT for 8 weeks is an effective approach for patients with AD, improving problem-solving ability, self-management efficacy, positive response, and social function, leading to increase in treatment compliance, and reducing relapse rate.

Conceptualizing traumatic stress and the structure of posttraumatic psychopathology through the lenses of RDoC and HiTOP

Trauma-related psychopathology, most notably posttraumatic stress disorder (PTSD), poses unique challenges for psychiatric nosology due to the wide range of symptoms and diagnoses associated with trauma and challenges representing the impact of trauma exposure on psychopathology. In this paper, we review the literature on categorical (i.e., Diagnostic and Statistical Manual of Mental Disorders and International Classification of Diseases systems) versus dimensional conceptualizations of trauma-related symptoms with an emphasis on the Research Domain Criteria (RDoC) and the Hierarchical Taxonomy of Psychopathology (HiTOP) frameworks. We identify strengths of each approach and challenges in accommodating the full range of trauma-related psychopathology and the clinical implications thereof. We discuss several potential approaches for improving the representation of traumatic stress, including the use of PTSD subtypes, trauma-related specifiers for psychiatric diagnoses, and the development of a dimension that we call the traumatic stress spectrum, which spans both adaptive and adverse reactions to trauma. These approaches to representing traumatic stress can be evaluated empirically and further refined. We also discuss how the use of an integrated RDoC-HiTOP approach to reconceptualize traumatic stress might maximize the ability to model valid and reliable trauma-related phenotypes, which would aid in the investigation of clinically relevant biological correlates.

Alcohol use and alcohol use disorder differ in their genetic relationships with PTSD: A genomic structural equation modelling approach

PURPOSE

Posttraumatic Stress Disorder (PTSD) is associated with increased alcohol use and alcohol use disorder (AUD), which are all moderately heritable. Studies suggest the genetic association between PTSD and alcohol use differs from that of PTSD and AUD, but further analysis is needed.

BASIC PROCEDURES

We used genomic Structural Equation Modeling (genomicSEM) to analyze summary statistics from large-scale genome-wide association studies (GWAS) of European Ancestry participants to investigate the genetic relationships between PTSD (both diagnosis and re-experiencing symptom severity) and a range of alcohol use and AUD phenotypes.

MAIN FINDINGS

When we differentiated genetic factors for alcohol use and AUD we observed improved model fit relative to models with all alcohol-related indicators loading onto a single factor. The genetic correlations (rG) of PTSD were quite discrepant for the alcohol use and AUD factors. This was true when modeled as a three-correlated-factor model (PTSD-AUD rG:.36, p < .001; PTSD-alcohol use rG: -0.17, p < .001) and as a Bifactor model, in which the common and unique portions of alcohol phenotypes were pulled out into an AUD-specific factor (rG with PTSD:.40, p < .001), AU-specific factor (rG with PTSD: -0.57, p < .001), and a common alcohol factor (rG with PTSD:.16, NS).

PRINCIPAL CONCLUSIONS

These results indicate the genetic architecture of alcohol use and AUD are differentially associated with PTSD. When the portions of variance unique to alcohol use and AUD are extracted, their genetic associations with PTSD vary substantially, suggesting different genetic architectures of alcohol phenotypes in people with PTSD.

[Comorbidity of posttraumatic stress disorder and addiction from a biopsychosocial perspective]

Posttraumatic stress disorder and substance use disorder often co-occur within the health care system. Their comorbidity is associated with more serious acute clinical symptomatology, more frequent hospital admissions in state of emergency and significantly lower chances of improvement by psychological and pharmacological treatment. Their comorbidity contributes to dramatically unfavourable courses of illness as regards all biopsychosocial levels. The survey presented will discuss empirical findings from various perspectives: general epidemiology, substance use disorder as risk factor of trauma and PTSD, trauma and PTSD as risk factor of SUD, neurobiological effects of SUD converging towards neurobiology of PTSD, shared common factors of genetics/epigenetics, personality traits, and early developmental stress and trauma. The main focus of analysis will be put on processes that are intrinsically linked to the development and course of both disorders.

A scoping review and comparison of approaches for measuring genetic heterogeneity in psychiatric disorders

An improved understanding of genetic etiological heterogeneity in a psychiatric condition may help us (a) isolate a neurophysiological 'final common pathway' by identifying its upstream genetic origins and (b) facilitate characterization of the condition's phenotypic variation. This review aims to identify existing genetic heterogeneity measurements in the psychiatric literature and provides a conceptual review of their mechanisms, limitations, and assumptions. The Scopus database was searched for studies that quantified genetic heterogeneity or correlation of psychiatric phenotypes with human genetic data. Ninety studies were included. Eighty-seven reports quantified genetic correlation, five applied genomic structural equation modelling, three evaluated departure from the Hardy-Weinberg equilibrium at one or more loci, and two applied a novel approach known as MiXeR. We found no study that rigorously measured genetic etiological heterogeneity across a large number of markers. Developing such approaches may help better characterize the biological diversity of psychopathology.

Potential causal effect of posttraumatic stress disorder on alcohol use disorder and alcohol consumption in individuals of European descent: A Mendelian Randomization Study

BACKGROUND

Posttraumatic stress disorder (PTSD) often co-occurs with alcohol consumption (AC) and alcohol use disorder (AUD). However, it is unknown whether the same etiologic influences that underlie PTSD co-occurring with AUD are those that underlie PTSD and AC individually.

METHODS

This study used large-scale genome-wide association study (GWAS) data to test whether PTSD and drinks per week [DPW]/AUD are causally related to one another, and, if so, whether PTSD precedes DPW/AUD and/or vice versa. We used Mendelian Randomization methods to analyze European ancestry GWAS summary statistics from the Psychiatric Genomics Consortium (PGC; PTSD), GWAS & Sequencing Consortium of Alcohol and Nicotine Use (GSCAN; DPW), and the Million Veteran Program (MVP; AUD).

RESULTS

PTSD exerted a potentially causal effect on AUD (β = 0.039, SE = 0.014, p = 0.005), but not on DPW (β = 0.002, SE = 0.003, p = 0.414). Additionally, neither DPW (β = 0.019, SE = 0.041, p = 0.637) nor AUD (β = 8.87 × 10-4 , SE = 0.001, p = 0.441) exerted a causal effect on PTSD.

CONCLUSIONS

These findings are consistent with the self-medication model, in which individuals misuse alcohol to cope with aversive trauma-related symptoms. These findings extend latent analysis and molecular findings of shared and correlated risk between PTSD and alcohol phenotypes. Given the health behaviors associated with these phenotypes, these findings are important in that they suggest groups to prioritize for prevention efforts. Further, they provide a rationale for future preclinical and clinical studies examining the biological mechanisms by which PTSD may impact AUD.

Juvenile stress facilitates safety learning in male and female high alcohol preferring mice

Adversities during juvenility increase the risk for stress-related disorders, such as post-traumatic stress disorder (PTSD) and alcohol use disorder. However, stress can also induce coping mechanisms beneficial for later stressful experiences. We reported previously that mice selectively bred for high alcohol preference (HAP) exposed to stress during adolescence (but not during adulthood) showed enhanced fear-conditioned responses in adulthood, as measured by fear-potentiated startle (FPS). However, HAP mice also showed enhanced responding to safety cues predicting the absence of foot shocks in adulthood. Here, we pursue these findings in HAP mice by investigating in further detail how juvenile stress impacts the acquisition of safety and fear learning. HAP mice were subjected to three days of juvenile stress (postnatal days 25, 27, 28) and discriminative safety/fear conditioning in adulthood. FPS was used to assess safety versus fear cue discrimination, fear learning, and fear inhibition by the safety cue. Both stressed and unstressed HAP mice were able to discriminate between both cues as well as learn the fear cue-shock association. Interestingly, it was only the previously stressed mice that were able to inhibit their fear response when the fear cue was co-presented with the safety cue, thus demonstrating safety learning. We also report an incidental finding of alopecia in the juvenile stress groups, a phenotype seen in stress-related disorders. These results in HAP mice may be relevant to understanding the influence of juvenile trauma for individual risk and resilience toward developing PTSD and how individuals might benefit from safety cues in behavioral psychotherapy.

Pathways to post-traumatic stress disorder and alcohol dependence: Trauma, executive functioning, and family history of alcoholism in adolescents and young adults

INTRODUCTION

Family history (FH) of alcohol dependence is likely to increase the risk of trauma exposure, post-traumatic stress disorder (PTSD), and alcohol dependence. FH of alcohol dependence and trauma has been separately shown to adversely affect planning/problem-solving aspects of executive function. However, few studies have examined these risk factors in an integrated model.

METHODS

Using data from trauma-exposed individuals from the Collaborative Study on the Genetics of Alcoholism prospective cohort (N = 1,860), comprising offspring from alcohol-dependent high-risk and comparison families (mean age [SE] = 21.9 [4.2]), we investigated associations of trauma (nonsexual assaultive, nonassaultive, sexual assaultive) with DSM-IV PTSD and alcohol dependence symptom counts, and planning/problem-solving abilities assessed using the Tower of London Test (TOLT). Moderating effects of family history density of alcohol use disorder (FHD) on these associations and sex differences were explored.

RESULTS

Family history density was positively associated with PTSD in female participants who endorsed a sexual assaultive trauma. Exposure to nonsexual assaultive trauma was associated with more excess moves made on the TOLT.

CONCLUSION

Findings from this study demonstrate associations with PTSD and alcohol dependence symptom counts, as well as poor problem-solving ability in trauma-exposed individuals from families densely affected with alcohol dependence, depending on trauma type, FHD, and sex. This suggests that having a FH of alcohol dependence and exposure to trauma during adolescence may be associated with more PTSD and alcohol dependence symptoms, and poor problem-solving abilities in adulthood.