Blood-based DNA methylation and exposure risk scores predict PTSD with high accuracy in military and civilian cohorts

Background

Incorporating genomic data into risk prediction has become an increasingly useful approach for rapid identification of individuals most at risk for complex disorders such as PTSD. Our goal was to develop and validate Methylation Risk Scores (MRS) using machine learning to distinguish individuals who have PTSD from those who do not.

Methods

Elastic Net was used to develop three risk score models using a discovery dataset (n = 1226; 314 cases, 912 controls) comprised of 5 diverse cohorts with available blood-derived DNA methylation (DNAm) measured on the Illumina Epic BeadChip. The first risk score, exposure and methylation risk score (eMRS) used cumulative and childhood trauma exposure and DNAm variables; the second, methylation-only risk score (MoRS) was based solely on DNAm data; the third, methylation-only risk scores with adjusted exposure variables (MoRSAE) utilized DNAm data adjusted for the two exposure variables. The potential of these risk scores to predict future PTSD based on pre-deployment data was also assessed. External validation of risk scores was conducted in four independent cohorts.

Results

The eMRS model showed the highest accuracy (92%), precision (91%), recall (87%), and f1-score (89%) in classifying PTSD using 3730 features. While still highly accurate, the MoRS (accuracy = 89%) using 3728 features and MoRSAE (accuracy = 84%) using 4150 features showed a decline in classification power. eMRS significantly predicted PTSD in one of the four independent cohorts, the BEAR cohort (beta = 0.6839, p-0.003), but not in the remaining three cohorts. Pre-deployment risk scores from all models (eMRS, beta = 1.92; MoRS, beta = 1.99 and MoRSAE, beta = 1.77) displayed a significant (p < 0.001) predictive power for post-deployment PTSD.

Conclusion

Results, especially those from the eMRS, reinforce earlier findings that methylation and trauma are interconnected and can be leveraged to increase the correct classification of those with vs. without PTSD. Moreover, our models can potentially be a valuable tool in predicting the future risk of developing PTSD. As more data become available, including additional molecular, environmental, and psychosocial factors in these scores may enhance their accuracy in predicting the condition and, relatedly, improve their performance in independent cohorts.

Gene-environment interaction study on the polygenic risk score for neuroticism, childhood adversity, and parental bonding

The present study examines whether neuroticism is predicted by genetic vulnerability, summarized as polygenic risk score for neuroticism (PRSN), in interaction with bullying, parental bonding, and childhood adversity. Data were derived from a general population adolescent and young adult twin cohort. The final sample consisted of 202 monozygotic and 436 dizygotic twins and 319 twin pairs. The Short Eysenck Personality questionnaire was used to measure neuroticism. PRSN was trained on the results from the Genetics of Personality Consortium (GPC) and United Kingdom Biobank (UKB) cohorts, yielding two different PRSN. Multilevel mixed-effects models were used to analyze the main and interacting associations of PRSN, childhood adversity, bullying, and parental bonding style with neuroticism. We found no evidence of gene-environment correlation. PRSN thresholds of .005 and .2 were chosen, based on GPC and UKB datasets, respectively. After correction for confounders, all the individual variables were associated with the expression of neuroticism: both PRSN from GPC and UKB, childhood adversity, maternal bonding, paternal bonding, and bullying in primary school and secondary school. However, the results indicated no evidence for gene-environment interaction in this cohort. These results suggest that genetic vulnerability on the one hand and negative life events (childhood adversity and bullying) and positive life events (optimal parental bonding) on the other represent noninteracting pathways to neuroticism.

Independent contribution of polygenic risk for schizophrenia and cannabis use in predicting psychotic-like experiences in young adulthood: testing gene × environment moderation and mediation

BACKGROUND

It has not yet been determined if the commonly reported cannabis-psychosis association is limited to individuals with pre-existing genetic risk for psychotic disorders.

METHODS

We examined whether the relationship between polygenic risk score for schizophrenia (PRS-Sz) and psychotic-like experiences (PLEs), as measured by the Community Assessment of Psychic Experiences-42 (CAPE-42) questionnaire, is mediated or moderated by lifetime cannabis use at 16 years of age in 1740 of the individuals of the European IMAGEN cohort. Secondary analysis examined the relationships between lifetime cannabis use, PRS-Sz and the various sub-scales of the CAPE-42. Sensitivity analyses including covariates, including a PRS for cannabis use, were conducted and results were replicated using data from 1223 individuals in the Dutch Utrecht cannabis cohort.

RESULTS

PRS-Sz significantly predicted cannabis use (p = 0.027) and PLE (p = 0.004) in the IMAGEN cohort. In the full model, considering PRS-Sz and covariates, cannabis use was also significantly associated with PLE in IMAGEN (p = 0.007). Results remained consistent in the Utrecht cohort and through sensitivity analyses. Nevertheless, there was no evidence of a mediation or moderation effects.

CONCLUSIONS

These results suggest that cannabis use remains a risk factor for PLEs, over and above genetic vulnerability for schizophrenia. This research does not support the notion that the cannabis-psychosis link is limited to individuals who are genetically predisposed to psychosis and suggests a need for research focusing on cannabis-related processes in psychosis that cannot be explained by genetic vulnerability.

Efficacy of oral versus long-acting antipsychotic treatment in patients with early-phase schizophrenia in Europe and Israel: a large-scale, open-label, randomised trial (EULAST)

BACKGROUND

Schizophrenia is a severe psychiatric disorder with periods of remission and relapse. As discontinuation of antipsychotic medication is the most important reason for relapse, long-term maintenance treatment is key. Whether intramuscular long-acting (depot) antipsychotics are more efficacious than oral medication in preventing medication discontinuation is still unresolved. We aimed to compare time to all-cause discontinuation in patients randomly allocated to long-acting injectable (LAI) versus oral medication.

METHODS

EULAST was a pragmatic, randomised, open-label trial conducted at 50 general hospitals and psychiatric specialty clinics in 15 European countries and Israel. Patients aged 18 years and older, with DSM-IV schizophrenia (as confirmed by the Mini International Neuropsychiatric Interview 5 plus) and having experienced their first psychotic episode from 6 months to 7 years before screening, were randomly allocated (1:1:1:1) using block randomisation to LAI paliperidone, LAI aripiprazole, or the respective oral formulations of these antipsychotics. Randomisation was stratified by country and duration of illness (6 months up to 3 years vs 4 to 7 years). Patients were followed up for up to 19 months. The primary endpoint was discontinuation, regardless of the reason, during 19 months of treatment. We used survival analysis to assess the time until all-cause discontinuation in the intention-to-treat (ITT) group, and per protocol analyses were also done. This trial is registered with ClinicalTrials.gov, NCT02146547, and is complete.

FINDINGS

Between Feb 24, 2015, and Dec 15, 2018, 533 individuals were recruited and assessed for eligibility. The ITT population included 511 participants, with 171 (33%) women and 340 (67%) men, and a mean age of 30·5 (SD 9·6) years. 410 (80%) of 511 participants were White, 35 (7%) were Black, 20 (4%) were Asian, and 46 (9%) were other ethnicity. In the combined oral antipsychotics treatment group of 247 patients, 72 (29%) patients completed the study and 175 (71%) met all-cause discontinuation criteria. In the combined LAI treatment arm of 264 patients, 95 (36%) completed the study and 169 (64%) met the all-cause discontinuation criteria. Cox regression analyses showed that treatment discontinuation for any cause did not differ between the two combined treatment groups (hazard ration [HR] 1·16, 95% CI 0·94-1·43, p=0·18). No significant difference was found in the time to all-cause discontinuation between the combined oral and combined LAI treatment groups (log rank test χ2=1·87 [df 1]; p=0·17). During the study, 121 psychiatric hospitalisations occurred in 103 patients, and one patient from each of the LAI groups died; the death of the patient assigned to paliperidone was assessed to be unrelated to the medication, but the cause of other patient's death was not shared with the study team. 86 (25%) of 350 participants with available data met akathisia criteria and 70 (20%) met parkinsonism criteria at some point during the study.

INTERPRETATION

We found no substantial advantage for LAI antipsychotic treatment over oral treatment regarding time to discontinuation in patients with early-phase schizophrenia, indicating that there is no reason to prescribe LAIs instead of oral antipsychotics if the goal is to prevent discontinuation of antipsychotic medication in daily clinical practice.

FUNDING

Lundbeck and Otsuka.

Common Genetic Variation and Age of Onset of Anorexia Nervosa

Background

Genetics and biology may influence the age of onset of anorexia nervosa (AN). The aims of this study were to determine whether common genetic variation contributes to age of onset of AN and to investigate the genetic associations between age of onset of AN and age at menarche.

Methods

A secondary analysis of the Psychiatric Genomics Consortium genome-wide association study (GWAS) of AN was performed, which included 9335 cases and 31,981 screened controls, all from European ancestries. We conducted GWASs of age of onset, early-onset AN (<13 years), and typical-onset AN, and genetic correlation, genetic risk score, and Mendelian randomization analyses.

Results

Two loci were genome-wide significant in the typical-onset AN GWAS. Heritability estimates (single nucleotide polymorphism-h 2) were 0.01-0.04 for age of onset, 0.16-0.25 for early-onset AN, and 0.17-0.25 for typical-onset AN. Early- and typical-onset AN showed distinct genetic correlation patterns with putative risk factors for AN. Specifically, early-onset AN was significantly genetically correlated with younger age at menarche, and typical-onset AN was significantly negatively genetically correlated with anthropometric traits. Genetic risk scores for age of onset and early-onset AN estimated from independent GWASs significantly predicted age of onset. Mendelian randomization analysis suggested a causal link between younger age at menarche and early-onset AN.

Conclusions

Our results provide evidence consistent with a common variant genetic basis for age of onset and implicate biological pathways regulating menarche and reproduction.

Nongenetic Factors Associated With Psychotic Experiences Among UK Biobank Participants: Exposome-Wide Analysis and Mendelian Randomization Analysis

Importance

Although hypothesis-driven research has identified several factors associated with psychosis, this one-exposure-to-one-outcome approach fails to embrace the multiplicity of exposures. Systematic approaches, similar to agnostic genome-wide analyses, are needed to identify genuine signals.

Objective

To systematically investigate nongenetic correlates of psychotic experiences through data-driven agnostic analyses and genetically informed approaches to evaluate associations.

Design, Setting, Participants

This cohort study analyzed data from the UK Biobank Mental Health Survey from January 1 to June 1, 2021. An exposome-wide association study was performed in 2 equal-sized split discovery and replication data sets. Variables associated with psychotic experiences in the exposome-wide analysis were tested in a multivariable model. For the variables associated with psychotic experiences in the final multivariable model, the single-nucleotide variant-based heritability and genetic overlap with psychotic experiences using linkage disequilibrium score regression were estimated, and mendelian randomization (MR) approaches were applied to test potential causality. The significant associations observed in 1-sample MR analyses were further tested in multiple sensitivity tests, including collider-correction MR, 2-sample MR, and multivariable MR analyses.

Exposures

After quality control based on a priori criteria, 247 environmental, lifestyle, behavioral, and economic variables.

Main Outcomes and Measures

Psychotic experiences.

Results

The study included 155 247 participants (87 896 [57%] female; mean [SD] age, 55.94 [7.74] years). In the discovery data set, 162 variables (66%) were associated with psychotic experiences. Of these, 148 (91%) were replicated. The multivariable analysis identified 36 variables that were associated with psychotic experiences. Of these, 28 had significant genetic overlap with psychotic experiences. One-sample MR analyses revealed forward associations with 3 variables and reverse associations with 3. Forward associations with ever having experienced sexual assault and pleiotropy of risk-taking behavior and reverse associations without pleiotropy of experiencing a physically violent crime as well as cannabis use and the reverse association with pleiotropy of worrying too long after embarrassment were confirmed in sensitivity tests. Thus, associations with psychotic experiences were found with both well-studied and unexplored multiple correlated variables. For several variables, the direction of the association was reversed in the final multivariable and MR analyses.

Conclusions and Relevance

The findings of this study underscore the need for systematic approaches and triangulation of evidence to build a knowledge base from ever-growing observational data to guide population-level prevention strategies for psychosis.

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.

Cerebrospinal fluid abnormalities in first- and multi-episode schizophrenia-spectrum disorders: impact of clinical and demographical variables

Multiple lines of evidence indicate that immunological and inflammatory alterations contribute at least in a subgroup to the pathophysiology of schizophrenia. In this retrospective chart review, we investigated whether clinical factors contribute to altered cerebrospinal fluid (CSF) findings in schizophrenia-spectrum disorders. Clinical data from electronic medical records of patients with psychotic disorders (ICD-10: F20-F29) who received routine CSF diagnostics at the Department of Psychiatry and Psychotherapy, LMU Munich, Germany, were included. Chi² tests for dichotomous outcomes and independent t tests for continuous outcomes were used to compare differences between groups. A total of 331 patients were included in the analyses (43.2% female and 56.8% male). The mean age was 37.67 years (±15.58). The mean duration of illness was 71.96 months (±102.59). In all, 40% (128/320) were first-episode psychosis (FEP) patients and 60% (192/320) were multi-episode psychosis (MEP) patients. Elevated CSF protein levels were found in 19.8% and elevated CSF/serum albumin ratios (QAlb) in 29.4% of the cases. Pleocytosis was found in 6.1% of patients. MEP patients showed significantly higher mean QAlb compared with FEP patients (t(304.57) = -2.75, p = 0.006), which did not remain significant after correcting for age. QAlb elevation occurred more frequently in men (X2(1) = 14.76, p = <0.001). For treatment resistance, family history, and cMRI alterations, no significant differences in CSF-related outcomes were detected. Our work extends other retrospective cohorts confirming a relevant degree of CSF alterations in schizophrenia-spectrum disorders and shows the difficulty to relate these alterations to clinical and disease course trajectories. More research is needed to develop treatment response predictors from CSF analyses.

The effect of prednisolone on symptom severity in schizophrenia: A placebo-controlled, randomized controlled trial

OBJECTIVE

Immune dysregulation may be involved in the pathophysiology of schizophrenia. Given the need for new treatment options in schizophrenia, anti-inflammatory medication could be a potential treatment in this illness.

METHODS

In this double-blind, placebo-controlled clinical trial, patients with schizophrenia, schizoaffective disorder or psychosis NOS were randomized 1:1 to either prednisolone or placebo, in addition to their regular antipsychotic medication. Patients diagnosed with schizophrenia for less than 7 years and on antipsychotics, were treated with prednisolone or placebo, tapered-off within six weeks in the following schedule: 40 mg/day for 3 days and 30 mg/day for 4 days, followed by a decrease of 5 mg/day per week during the remaining 5 weeks. Change in symptom severity relative to baseline was compared between treatment arms, as measured through the Positive and Negative Syndrome Scale total score.

RESULTS

In total, 68 patients signed informed consent and were screened on eligibility criteria, of whom 42 patients were randomized to either prednisolone or placebo, with 39 patients completing the treatment and tapering phase. Due to recruitment difficulties, the study was terminated prematurely. Symptom severity decreased significantly in both the prednisone and placebo treatment arm (p < 0.001). The degree of improvement was not significantly different between treatment arms (p = 0.96). No serious adverse events occurred during the treatment phase.

DISCUSSION

There is no indication that prednisolone has a beneficial effect on symptom severity, as adjunctive treatment in patients with schizophrenia, as compared to placebo.

CONCLUSION

Adjunctive treatment with prednisolone did not improve symptom severity compared to placebo in patients with schizophrenia.

Effectiveness of antipsychotics in schizophrenia with comorbid substance use disorder

Introduction

Schizophrenia is highly comorbid with substance use disorders (SUD), which may negatively impact the course of illness. However, large studies exploring the best lines of treatment for this combination are lacking.

Objectives

We investigated what are the most effective antipsychotics for patients with schizophrenia in preventing the development of substance use disorders and preventing hospitalizations in patients already having substance use disorder.

Methods

We used two independent national cohort registries including all patient with schizophrenia aged under 46 years. Participants were followed during 22 (1996–2017, Finland) and 11 years (2006–2016, Sweden). We studied risk of rehospitalization, and risk of developing an SUD when using vs. not using antipsychotics, using Cox proportional hazards regression analysis models.

Results

45,476 patients with schizophrenia were identified (30,860 in Finland; 14,616 in Sweden). For patients without SUD, clozapine and antipsychotic polytherapy were associated with the lowest risks of developing SUD in both countries. For patients with co-existing SUD, the risk of hospitalization was the lowest during clozapine, polytherapy and long-acting injectable use.

Conclusions

In patients with schizophrenia and comorbid SUD, antipsychotic medications were effective in preventing relapses. In those without an SUD, antipsychotic use was associated with a markedly reduced risk of developing an initial SUD. Clozapine and long-acting injectables should be considered treatments of choice in patients with schizophrenia and SUD, or at risk of developing co-morbid SUD.

Disclosure

ML: Genomi Solutions Ltd, DNE Ltd, Sunovion, Orion Pharma, Janssen-Cilag, Finnish Medical Foundation, Emil Aaltonen Foundation. HT, EMR, AT: Eli Lilly, Janssen–Cilag. JT: Eli Lilly, Janssen-Cilag, Lundbeck, Otsuka.

Morbidity and mortality in schizophrenia with comorbid substance use disorders in Finland and Sweden

Introduction

Schizophrenia is highly comorbid with substance use disorders (SUD) but large epidemiological cohorts exploring the prevalence and prognostic significance of SUD are lacking.

Objectives

To investigate the prevalence of SUD in patients with schizophrenia in Finland and Sweden, and the effect of these co-occurring disorders on risks of psychiatric hospitalization and mortality.

Methods

45,476 individuals with schizophrenia from two independent national cohort studies, aged <46 years at cohort entry, were followed during 22 (1996-2017, Finland) and 11 years (2006-2016, Sweden). We first assessed SUD prevalence (excluding smoking). Then we performed Cox regression on risk of psychiatric hospitalization and mortality in patients with schizohrenia and SUD compared with those without SUD.

Results

The prevalence of SUD in specialized healthcare ranged from 26% (Finland) to 31% (Sweden). Multiple drug use and alcohol use disorders were the most prevalent SUD, followed by cannabis use disorders. Any SUD comorbidity, and particularly multiple drug use and alcohol use, were associated with 50% to 100% increases in hospitalization and mortality compared to individuals without SUD. Elevated mortality risks were observed especially for deaths due to suicide and other external causes. All results were similar across countries.

Conclusions

Co-occurring SUD, and particularly alcohol and multiple drug use, are associated with high rates of hospitalization and mortality in patients with schizophrenia. Preventive interventions should prioritize detection and tailored treatments for these co-morbidities, which often remain underdiagnosed and untreated.

Conflict of interest

ML: Genomi Solutions Ltd, Nursie Health Ltd, Sunovion, Orion Pharma, Janssen-Cilag, Finnish Medical Foundation, Emil Aaltonen Foundation. HT, EMR, AT: Eli Lilly, Janssen–Cilag. JT: Eli Lilly, Janssen-Cilag, Lundbeck, Otsuka.

RNA Sequencing in Bipolar Disorder: From Long Non-coding to Circular rnas

Bipolar disorder (BPD) is a highly debilitating psychiatric disorder. The underlying molecular mechanisms of BPD remain largely unknown. Studies targeting postmortem brain tissues of BPD patients have identified very few consistently replicated differences in the expression levels of protein-coding RNAs across different areas of the brain. Since differential expression of the human genome produces a wide spectrum of protein-coding and noncoding RNAs, we hypothesized that major molecular deficits associated with BPD could reflect dysregulation of multiple classes of RNA. To test this hypothesis, we obtained postmortem human medial frontal gyrus tissue from BPD patients and healthy controls (n = 16). To survey the implication of both protein-coding and long non-coding RNAs (lncRNAs) in BPD, we then performed RNA sequencing, PCR validation and replication experiments adopting a case-control design. Thirty-six genes and fifteen lncRNA transcripts not previously implicated in BPD were detected as differentially expressed (FDR < 0.1). Functional analyses identified enrichments of angiogenesis, vascular system development and histone H3-K4 demethylation. In addition, we report extensive alternative splicing defects in the brains of BPD subjects compared to controls. Finally, we describe for the first time a large reservoir of circular RNAs (circRNAs) that populate the medial frontal gyrus and report significantly altered levels of two circular transcripts (cNEBL and cEPHA3) from the NEBL and EPHA3 loci in BPD. Our findings may not only contribute to gain insight into the pathophysiology of BPD but may be tested in the near future as potential biomarkers for diagnostics.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Genome-wide association study identifies eight risk loci and implicates metabo-psychiatric origins for anorexia nervosa

Characterized primarily by a low body-mass index, anorexia nervosa is a complex and serious illness1, affecting 0.9-4% of women and 0.3% of men2-4, with twin-based heritability estimates of 50-60%5. Mortality rates are higher than those in other psychiatric disorders6, and outcomes are unacceptably poor7. Here we combine data from the Anorexia Nervosa Genetics Initiative (ANGI)8,9 and the Eating Disorders Working Group of the Psychiatric Genomics Consortium (PGC-ED) and conduct a genome-wide association study of 16,992 cases of anorexia nervosa and 55,525 controls, identifying eight significant loci. The genetic architecture of anorexia nervosa mirrors its clinical presentation, showing significant genetic correlations with psychiatric disorders, physical activity, and metabolic (including glycemic), lipid and anthropometric traits, independent of the effects of common variants associated with body-mass index. These results further encourage a reconceptualization of anorexia nervosa as a metabo-psychiatric disorder. Elucidating the metabolic component is a critical direction for future research, and paying attention to both psychiatric and metabolic components may be key to improving outcomes.

Absence of cerebrospinal fluid antineuronal antibodies in schizophrenia spectrum disorders - CORRIGENDUM

This notice describes a correction to the above mentioned paper.

Absence of cerebrospinal fluid antineuronal antibodies in schizophrenia spectrum disorders

Antibody-mediated encephalitis has been discussed as one possible cause for isolated psychotic syndromes. Mostly based on serum samples, findings have been controversial. We present the results of a retrospective study of 124 clinically diagnosed psychotic patients without documented relevant neurological symptoms. All were tested for different antineuronal antibodies in cerebrospinal fluid (CSF) while 81 received serum testing. Antineuronal antibodies in CSF were negative across the sample. 3.7% showed low positive serum antibodies. Our findings highlight the importance of a deeper discussion about the relevance of low positive serum antibodies without concurrent findings in CSF or clinical signs for autoimmune encephalitis.Declaration of interestNone.