Publications by authors named "Nikolaos Daskalakis"

Genes involved in regulating the hypothalamic-pituitary-adrenal (HPA) axis, including the glucocorticoid receptor (GR), are linked to various stress-related psychopathologies including bipolar disorder as well as other mood and trauma-related disorders. The protein product of the cell cycle gene, is a GR interaction partner in peripheral cells. However, the precise roles of SKA2 in stress and GR signaling in the brain, specifically in nonreplicating postmitotic neurons, and its involvement in HPA axis regulation remain unclear.

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  • The study explores the biological differences linked to PTSD by examining DNA methylation changes in blood, suggesting they could indicate susceptibility or effects of trauma.
  • Conducted by the Psychiatric Genomics Consortium, the research included nearly 5,100 participants to identify specific genetic markers associated with PTSD.
  • Results showed 11 significant CpG sites related to PTSD, with some also showing correlations between blood and brain tissue methylation, highlighting their potential role in understanding PTSD biology.
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  • Alzheimer's Disease is influenced by genetic, environmental, and lifestyle factors, including exercise, diet, education, and early life stress, which can affect its onset and progression.
  • Recent research has identified crucial biological processes, like stress hormones and neuroinflammation, that may link early life stress to an increased risk of developing Alzheimer's Disease.
  • Gaining insights into how early life experiences shape brain health could lead to new prevention and treatment strategies to counteract the impact of stress and reduce dementia risk.
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  • Exposure to stressful life events can significantly increase the chances of developing psychiatric disorders, particularly affecting cognitive functions, which can be difficult to comprehend for both individuals and healthcare providers.
  • The review highlights the need to study specific brain areas (like the amygdala and hippocampus) to understand the structural and molecular changes induced by stress, which can persistently alter brain function.
  • It calls for more research into genetic risk factors and the use of advanced technologies to better comprehend how stress impacts various brain regions, aiming to improve prevention and treatment approaches for cognitive symptoms related to stress.
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  • Researchers aimed to create and validate Methylation Risk Scores (MRS) using machine learning to identify individuals at risk for PTSD based on genomic and trauma exposure data.
  • The study developed three models: eMRS (which combines trauma exposure and methylation data), MoRS (which relies only on methylation data), and MoRSAE (which adjusts MoRS for trauma exposure).
  • The eMRS model showed the best performance with a 92% accuracy, and all models were able to predict post-deployment PTSD significantly, suggesting that including trauma exposure improves risk assessment.
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Large-scale cohort and epidemiological studies suggest that posttraumatic stress disorder (PTSD) confers risk for late-onset Alzheimer's disease (AD) and related dementias (ADRD); however, the basis for this association remains unclear. Several prior studies of military Veterans have reported that carriers of the apolipoprotein E () ε4 gene variant are at heightened risk for the development of PTSD following combat exposure, suggesting that PTSD and ADRD may share some genetic risk. This cohort study was designed to further examine the hypothesis that ADRD genetic risk also confers risk for PTSD.

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  • - Aging significantly impacts the brain, increasing the risk for neurodegenerative disorders, especially in individuals with psychiatric conditions.
  • - A study analyzed transcriptomic changes in the orbitofrontal cortex from nearly 800,000 brain cell nuclei of 87 people, revealing that aging affects all brain cell types, particularly certain interneurons.
  • - Findings indicate that the transcriptomic aging process is accelerated in those with psychiatric disorders, highlighting shared biological pathways between aging and mental health issues.
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  • The study investigates the link between post-traumatic stress disorder (PTSD) and differences in DNA methylation, a type of gene regulation, in blood samples from individuals diagnosed with PTSD compared to trauma-exposed controls.
  • Researchers conducted a large-scale analysis involving over 5,000 participants from various civilian and military studies, using standardized procedures for PTSD assessment and DNA methylation testing.
  • The results revealed 11 specific DNA methylation sites associated with PTSD, and found similarities in methylation patterns between blood and brain tissues, suggesting a biological basis for the condition.
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The molecular pathology of stress-related disorders remains elusive. Our brain multiregion, multiomic study of posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) included the central nucleus of the amygdala, hippocampal dentate gyrus, and medial prefrontal cortex (mPFC). Genes and exons within the mPFC carried most disease signals replicated across two independent cohorts.

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  • PTSD genetics have been difficult to study compared to other psychiatric disorders, limiting our biological understanding of the condition.
  • A large-scale meta-analysis involving over 1.2 million individuals identified 95 genome-wide significant loci, with 80 being new discoveries related to PTSD.
  • Researchers identified 43 potential causal genes linked to neurotransmitter activity, developmental processes, synaptic function, and immune regulation, enhancing our knowledge of the neurobiological systems involved in PTSD.
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This study examines the association between brain dynamic functional network connectivity (dFNC) and current/future posttraumatic stress (PTS) symptom severity, and the impact of sex on this relationship. By analyzing 275 participants' dFNC data obtained ~2 weeks after trauma exposure, we noted that brain dynamics of an inter-network brain state link negatively with current (r=-0.179, = 0.

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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.

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Tinnitus is a heritable, highly prevalent auditory disorder treated by multiple medical specialties. Previous GWAS indicated high genetic correlations between tinnitus and hearing loss, with little indication of differentiating signals. We present a GWAS meta-analysis, triple previous sample sizes, and expand to non-European ancestries.

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Background: Allostatic load is the cumulative "wear and tear" on the body due to chronic adversity We aimed to test poly-environmental (exposomic) and polygenic contributions to allostatic load and their combined contribution to early adolescent mental health.

Methods: We analyzed data on N = 5,035 diverse youth (mean age 12) from the Adolescent Brain Cognitive Development Study (ABCD). Using dimensionality reduction method, we calculated and overall allostatic load score (AL) using body mass index [BMI], waist circumference, blood pressure, blood glycemia, blood cholesterol, and salivary DHEA.

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  • PTSD genetics are harder to study compared to other mental health disorders, resulting in limited biological insights from past research.
  • A large-scale analysis involving over 1.2 million individuals found 95 significant genetic loci related to PTSD, with 80 being new discoveries.
  • The study identified 43 potential causal genes linked to neurotransmitters, synaptic function, and immune responses, enhancing understanding of PTSD's biological mechanisms and suggesting new research directions.
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Objective: Multidisciplinary studies of posttraumatic stress disorder (PTSD) and major depressive disorder (MDD) implicate the dorsolateral prefrontal cortex (DLPFC) in disease risk and pathophysiology. Postmortem brain studies have relied on bulk-tissue RNA sequencing (RNA-seq), but single-cell RNA-seq is needed to dissect cell-type-specific mechanisms. The authors conducted the first single-nucleus RNA-seq postmortem brain study in PTSD to elucidate disease transcriptomic pathology with cell-type-specific resolution.

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The pituitary adenylate cyclase-activating polypeptide (PACAP) system is implicated in posttraumatic stress disorder (PTSD) and related amygdala-mediated arousal and threat reactivity. PTSD is characterized by increased amygdala reactivity to threat and, more recently, aberrant intrinsic connectivity of the amygdala with large-scale resting state networks, specifically the default mode network (DMN). While the influence of PACAP on amygdala reactivity has been described, its association with intrinsic amygdala connectivity remains unknown.

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Genomic regulatory elements active in the developing human brain are notably enriched in genetic risk for neuropsychiatric disorders, including autism spectrum disorder (ASD), schizophrenia, and bipolar disorder. However, prioritizing the specific risk genes and candidate molecular mechanisms underlying these genetic enrichments has been hindered by the lack of a single unified large-scale gene regulatory atlas of human brain development. Here, we uniformly process and systematically characterize gene, isoform, and splicing quantitative trait loci (xQTLs) in 672 fetal brain samples from unique subjects across multiple ancestral populations.

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Hypothalamic-pituitary adrenal (HPA)axis dysregulation has long been implicated in stress-related disorders such as major depression and post-traumatic stress disorder. Glucocorticoids (GCs) are released from the adrenal glands as a result of HPA-axis activation. The release of GCs is implicated with several neurobiological changes that are associated with negative consequences of chronic stress and the onset and course of psychiatric disorders.

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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.

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'You can't roll the clock back and reverse the effects of experiences' Bruce McEwen used to say when explaining how allostasis labels the adaptive process. Here we will for once roll the clock back to the times that the science of the glucocorticoid hormone was honored with a Nobel prize and highlight the discovery of their receptors in the hippocampus as inroad to its current status as master regulator in control of stress coping and adaptation. Glucocorticoids operate in concert with numerous neurotransmitters, neuropeptides, and other hormones with the aim to facilitate processing of information in the neurocircuitry of stress, from anticipation and perception of a novel experience to behavioral adaptation and memory storage.

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