A disturbance in the paradigm of child abuse

The principal way science advances is through the principle Einstein expressed as:

“No amount of experimentation can ever prove me right; a single experiment can prove me wrong.”

Members of the scientific community and of the public should be satisfied that the scientific process is working well when hypotheses are discarded due to nonconfirming evidence. Researchers should strive to develop evidence that rejects paradigms, and be lauded for their efforts.

The opposite took place with this 2018 commentary on two studies where the evidence didn’t confirm current biases. I curated one of these studies in DNA methylation and childhood adversity.

The commentators’ dismissive tone was set in the opening paragraph:

“Is early exposure to adversity associated with a genetic or an epigenetic signature? At first glance, two articles in this issue -..and the other from Marzi et al., who measured genome-wide DNA methylation in a prospective twin cohort assessed at age 18 – appear to say that it is not.”

The two commentators, one of whom was a coauthor of Manufacturing PTSD evidence with machine learning, went on to protect their territory. Never mind the two studies’ advancement of science that didn’t coincide with the commentators’ vested interests.


My main concern with the study was that although the children had been studied at ages 5, 7, 10, 12, and 18, the parents had never been similarly evaluated! The researchers passed up an opportunity to develop the parents as a F0 generation for understanding possible human transgenerational inherited epigenetic causes and effects.

The study focused on the children’s intergenerational epigenetic effects. However, animal studies have often demonstrated transgenerational effects that skip over the F1 generation children!

For example:

https://ajp.psychiatryonline.org/doi/pdf/10.1176/appi.ajp.2018.18020156 “Considering the Genetic and Epigenetic Signature of Early Adversity Within a Biopsychosocial Framework” (not freely available)

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The hypothalamus and aging

This 2018 Korean review discussed aspects of the hypothalamus and aging:

“A majority of physiological functions that decline with aging are broadly governed by the hypothalamus, a brain region controlling development, metabolism, reproduction, circadian rhythm, and homeostasis. In addition, the hypothalamus is poised to connect the brain and the body so that the environmental information affecting aging can be transmitted through the hypothalamus to affect the systematic aging of the peripheral organs.

The hypothalamus is hypothesized to be a primary regulator of the process of aging of the entire body. This review aims to assess the contribution of hypothalamic aging to the age-related decline in body functions, particularly from the perspective of:

  • energy homeostasis,
  • hormonal balance,
  • circadian rhythm, and
  • reproduction,

and to highlight its underlying cellular mechanisms with a focus on:

  • nutrient sensing
  • inflammation,
  • loss of stem cell,
  • loss of proteostasis, and
  • epigenetic alterations.”


The reviewers didn’t consider aging to be an “unintended consequence” of development. This perspective was found in a reference to A study of DNA methylation and age:

“Aging is not and cannot be programmed. Instead, aging is a continuation of developmental growth, driven by genetic pathways.

Genetic programs determine developmental growth and the onset of reproduction. When these programs are completed, they are not switched off.

Aging has no purpose (neither for individuals nor for group), no intention. Nature does not select for quasi-programs. It selects for robust developmental growth.”

The epigenetic clock theory of aging cited the same author, and modified his point to say:

“The proposed epigenetic clock theory of ageing views biological ageing as an unintended consequence of both developmental programmes and maintenance programmes.”

This review’s opposite paradigm was:

“The hypothalamus is hypothesized to be a primary regulator of the process of aging.”

Almost all of the details discussed were from rodent studies.


I favor the “unintended consequence” explanation of aging. As detailed in How to cure the ultimate causes of migraines? and its references, the hypothalamus is a brain structure that lacks feedback mechanisms for several of its activities.

This structure develops shortly after conception and has an active prenatal role. The hypothalamus plays its part in getting us developed and ready to reproduce, with several feedback loops being evolutionarily unnecessary.

The hypothalamus perfectly illustrates the point of:

“When these programs are completed, they are not switched off.”

Should hypothalamic activity not winding down when its developmental role is over be interpreted to construe a role that has some other meaning or purpose as we age?

https://www.sciencedirect.com/science/article/pii/S0047637418300502 “Role of hypothalamus in aging and its underlying cellular mechanisms” (not freely available)

The lack of oxygen’s epigenetic effects on a fetus

This 2018 Loma Linda review subject was gestational hypoxia:

“Of all the stresses to which the fetus and newborn infant are subjected, perhaps the most important and clinically relevant is that of hypoxia. This review explores the impact of gestational hypoxia on maternal health and fetal development, and epigenetic mechanisms of developmental plasticity with emphasis on the uteroplacental circulation, heart development, cerebral circulation, pulmonary development, and the hypothalamic-pituitary-adrenal axis and adipose tissue.

An understanding of the specific hypoxia-induced environmental and epigenetic adaptations linked to specific organ systems will enhance the development of target-specific inhibition of DNA methylation, histone modifications, and noncoding RNAs that underlie hypoxia-induced phenotypic programming of disease vulnerability later in life.

A potential stumbling block to these efforts, however, relates to timing of the intervention. The greatest potential effect would be accomplished at the critical period in development for which the genomic plasticity is at its peak, thus ameliorating the influence of hypoxia or other stressors.

With future developments, it may even become possible to intervene before conception, before the genetic determinants of the risk of developing programmed disease are established.”

Table 3 “Antenatal hypoxia and developmental plasticity” column titles were Species | Offspring Phenotypes of Disorders and Diseases | Reference Nos.

Hypoxia phenotypes


This review was really an ebook, with 94 pages and 1,172 citations in the pdf file. As I did with Faith-tainted epigenetics, I read it with caution toward recognizing the influence of the sponsor’s biases, and any directed narrative that ignored evidence contradicting the narrative, and any storytelling.

See if you can match the meaning of the review’s last sentence quoted above with the meaning of any sentence in its cited reference Developmental origins of noncommunicable disease: population and public health implications.

One review topic that was misconstrued was transgenerational epigenetic inheritance of hypoxic effects. The “transgenerational” term was used inappropriately by several of the citations, and no cited study provided evidence for gestational hypoxic effects through the  F2 grandchild and F3 great-grandchild generations.

One omitted topic was gestational hypoxic effects of caffeine. The first paper that came up for my PubMed search of “caffeine pregnancy hypoxia” was an outstanding 2017 Florida rodent review Long-term consequences of disrupting adenosine signaling during embryonic development that had this paragraph and figure:

“One substance that fetuses are frequently exposed to is caffeine, which is a non-selective adenosine receptor antagonist. We discovered that in utero alteration in adenosine action leads to adverse effects on embryonic and adult murine hearts. We find that cardiac A1ARs [a type of adenosine receptor] protect the embryo from in utero hypoxic stress, a condition that causes an increase in adenosine levels. 

After birth in mice, we observed that in utero caffeine exposure leads to abnormal cardiac function and morphology in adults, including an impaired response to β-adrenergic stimulation. Recently, we observed that in utero caffeine exposure induces transgenerational effects on cardiac morphology, function, and gene expression.”

The timing of in utero caffeine treatment leads to differences in adult cardiac function, gene expression, and phenotype. Exposure to caffeine from E6.5–9.5 leads the F1 generation to develop dilated cardiomyopathy with decrease % FS and increased Myh7 expression. In utero caffeine exposure from E10.5–13.5 leads to a hypertrophic cardiomyopathy in the F2 generation along with increased % FS and decreased Myh7 expression

Why was this review and its studies omitted? It was on target for both gestational hypoxia and transgenerational epigenetic inheritance of hypoxic effects!

It was alright to review smoking, cocaine, methamphetamine, etc., but the most prevalent drug addiction – caffeine – couldn’t be a review topic?


The Loma Linda review covered a lot, but I had a quick trigger due to the sponsor’s bias. I started to lose “faith” in the reviewers after reading the citation for the review’s last sentence that didn’t support the statement.

My “faith” disappeared after not understanding why a few topics were misconstrued and omitted. Why do researchers and sponsors ignore, misrepresent, and not continue experiments through the F3 generation to produce evidence for and against transgenerational epigenetic inheritance? Where was the will to follow evidence trails regardless of socially acceptable beverage norms?

The review acquired the taint of storytelling with the reviewers’ assertion:

“..timing of the intervention. The greatest potential effect would be accomplished at the critical period in development for which the genomic plasticity is at its peak, thus ameliorating the influence of hypoxia or other stressors.”

Contradictory evidence was in the omitted caffeine study’s graphic above which described two gestational periods where an “intervention” had opposite effects, all of which were harmful to the current fetus’ development and/or to following generations. Widening the PubMed link’s search parameters to “caffeine hypoxia” and “caffeine pregnancy” returned links to human early life studies that used caffeine in interventions, ignoring possible adverse effects on future generations.

This is my final curation of any paper sponsored by this institution.

https://www.physiology.org/doi/abs/10.1152/physrev.00043.2017 “Gestational Hypoxia and Developmental Plasticity” (not freely available) Thanks to coauthor Dr. Xiang-Qun Hu for providing a copy.

Ideaesthesia!

This 2018 UK review subject was colored-hearing arising on hearing music:

“Music-colour synaesthesia has a broad scope encompassing not only tone-colour synaesthesia elicited on hearing individual tones, but a complex and idiosyncratic mixture of phenomenological experiences often mediated by timbre, tempo, emotion and differing musical style.

The possession of synaesthesia or absolute pitch was shown to have very little effect on the actual colours chosen for each of the musical excerpts, but it might be reasonable to expect that music that elicits a strong emotional response may be more likely to induce synaesthesia than music that does not.

The examination of eight neuroimaging studies were found to be largely inconclusive in respect of confirming the perceptual nature of music-colour synaesthesia. Neither the hyperconnectivity nor the disinhibited feedback theory currently holds as a single categorical explanation for synaesthesia.

Theories promoting the notion of ‘ideaesthesia’ have highlighted the importance of the role of concept and meaning in the understanding of synaesthesia..and a replacement definition: Synaesthesia is a phenomenon in which a mental activation of a certain concept or idea is associated consistently with a certain perception-like experience.”

Much of the review was philosophizing and casting around for clues. The review cited interesting studies and reviews, including The Merit of Synesthesia for Consciousness Research.


One relevant element missed by the underlying research and the review was critical periods of human development. A cited reference in How brains mature during critical periods was Sensitive periods in human development: Evidence from musical training (not freely available) which illuminated some aspects of the research:

“In contrast to a critical period, where a function cannot be acquired outside the specific developmental window, a sensitive period denotes a time where sensory experience has a relatively greater influence on behavioral and cortical development. Sensitive periods may also be times when exposure to specific stimuli stimulates plasticity, enhancing changes at the neuronal and behavioral levels.

The developmental window for absolute pitch may be more similar to a critical than a sensitive period.

The auditory cortex appears to have an unusually long period of developmental plasticity compared with other sensory systems; changes in its cellular organization and connectivity continue into late childhood.

The effects of musical training have been shown to impact auditory processing in the brainstem as well.”

Let’s say that a researcher wanted – as one cited study did – to examine absolute pitch, a rare trait, present in a subset of synesthetes – music-color, another rare trait. The study as designed would probably be underpowered due to an insufficient number of subjects, and it would subsequently find “very little effect.”

Let’s say another researcher focused on brain areas in the cerebrum, and like the eight cited studies, ignored the nuclei in the pons part of the brainstem which are the first brain recipients of sound and equilibrium information from the inner ear via the eighth cranial nerve. Like those studies, they were also biased against including limbic brain areas that would indicate “a strong emotional response.” A study design that combined leaving out important brain-area participants in the synesthesia process with a few number of synesthetes would be unlikely to find conclusive evidence.

The reviewer viewed the lack of evidence from “eight neuroimaging studies” as indicating something about the “perceptual nature of music-colour synaesthesia.” An alternative view is that the “inconclusive” evidence had more to do with study designs that:

  • Had a small number of subjects;
  • Omitted brain areas relevant to the music-color synesthesia process;
  • Didn’t investigate likely music-color synesthesia development periods; and
  • Didn’t investigate associations of music-color synesthesia with epigenetic states.

Consider the magnitude of omitting the thalamus from synesthesia studies as one “perceptual nature” example. Just the background information of Thalamus gating and control of the limbic system and cerebrum is a form of memory indicated its relevance to synesthesia:

Despite the fundamental differences between visual, auditory and somatosensory signals, the basic layouts of the thalamocortical systems for each modality are quite similar.

For a given stimulus, the output neural response will not be static, but will depend on recent stimulus and response history.

Sensory signals en route to the cortex undergo profound signal transformations in the thalamus. A key thalamic transformation is sensory adaptation in which neural output adjusts to the statistics and dynamics of past stimuli.”

One of this study’s researchers described ways that an individual’s “stimulus and response history” became unconscious memories with the thalamus. Including the thalamus in synesthesia studies may also have findings that involve reliving or re-experiencing a memory, possibly an emotional memory.

In such future research, it could be a design element to ask synesthetes before and after the experiment to identify feelings and memories accompanying synesthesia experiences.

It shouldn’t be a requirement, however, to insist that memories and emotions be consciously identified in order to be included in the findings. Human studies, for example, Unconscious stimuli have a pervasive effect on our brain function and behavior have found:

“Pain responses can be shaped by learning that takes place outside conscious awareness.

Our results support the notion that nonconscious stimuli have a pervasive effect on human brain function and behavior and may affect learning of complex cognitive processes such as psychologically mediated analgesic and hyperalgesic responses.”


Does an orangey twilight of fading sunflowers help you feel?

https://www.sciencedirect.com/science/article/pii/S1053810017305883 “Music-colour synaesthesia: Concept, context and qualia” (not freely available)

in utero prevention of breast cancer by a broccoli sprouts diet

This 2018 Alabama rodent study investigated the epigenetic effects on developing breast cancer of timing a sulforaphane-based broccoli sprouts diet. Timing of the diet was as follows:

  1. Conception through weaning (postnatal day 28), named the Prenatal/maternal BSp (broccoli sprouts) treatment (what the mothers ate starting when they were adults at 12 weeks until their pups were weaned; the pups were never on a broccoli sprouts diet);
  2. Postnatal day 28 through the termination of the experiment, named the Postnatal early-life BSp treatment (what the offspring ate starting at 4 weeks; the mothers were never on a broccoli sprouts diet); and
  3. Postnatal day 56 through the termination of the experiment, named the Postnatal adult BSp treatment (what the offspring ate starting when they were adults at 8 weeks; the mothers were never on a broccoli sprouts diet).

“The experiment was terminated when the mean tumor diameter in the control mice exceeded 1.0 cm.

Our study indicates a prenatal/maternal BSp dietary treatment exhibited maximal preventive effects in inhibiting breast cancer development compared to postnatal early-life and adult BSp treatments in two transgenic mouse models that can develop breast cancer.

Postnatal early-life BSp treatment starting prior to puberty onset showed protective effects in prevention of breast cancer but was not as effective as the prenatal/maternal BSp treatment. However, adulthood-administered BSp diet did not reduce mammary tumorigenesis.

The prenatal/maternal BSp diet may:

  • Primarily influence histone modification processes rather than DNA methylation processes that may contribute to its early breast cancer prevention effects;
  • Exert its transplacental breast cancer chemoprevention effects through enhanced histone acetylation activator markers due to reduced HDAC1 expression and enzymatic activity.

This may be also due to the importance of a dietary intervention window that occurs during a critical oncogenic transition period, which is in early life for these two tested transgenic mouse models. Determination of a critical oncogenic transition period could be complicated in humans, which may partially explain the controversial findings of the adult BSp treatment on breast cancer development in the tested mouse models as compared the previous studies. Thus long-term consumption of BSp diet is recommended to prevent cancers in humans.”


“The dietary concentration for BSp used in the mouse studies was 26% BSp in formulated diet, which is equivalent to 266 g (~4 cups) BSp/per day for human consumption. Therefore, the concentration of BSp in this diet is physiological available and represents a practical consumption level in the human diet.

Prior to the experiment, we tested the potential influences of this prenatal/maternal BSp regimen on maternal and offspring health as well as mammary gland development in the offspring. Our results showed there was no negative effect of this dietary regimen on the above mentioned factors (data not shown) suggesting this diet is safe to use during pregnancy.”


I downgraded the study’s rating because I didn’t see where the sulforaphane active content of the diet was defined. It’s one thing to state:

“SFN as the most abundant and bioactive compound in the BSp diet has been identified as a potent HDAC inhibitor that preferably influences histone acetylation processes.”

and describe how sulforaphane may do this and may do that, and include it in the study’s title.

It’s another thing to quantify an animal study into findings that can help humans. Normal people aren’t going to eat “4 cups BSp/per day” but we may take one capsule of a sulforaphane dietary supplement when the price is $.20 a day.

The study’s food manufacturer offers dietary products to the public without quantifying all of the active contents like sulforaphane. Good for them if they can stay in business by serving customers who can’t be bothered with scientific evidence.

These researchers shouldn’t have conducted a study using the same lack of details as the food manufacturer provided, though. They should have either tasked the manufacturer to specify the sulforaphane active content, or contracted the analysis.

Regarding timing of a sulforaphane-based broccoli sprouts diet for humans, the study also didn’t provide evidence for recommending:

“Thus long-term consumption of BSp diet is recommended to prevent cancers in humans.”

http://cancerpreventionresearch.aacrjournals.org/content/early/2018/05/15/1940-6207.CAPR-17-0423.full-text.pdf “Temporal efficacy of a sulforaphane-based broccoli sprout diet in prevention of breast cancer through modulation of epigenetic mechanisms”

A trio of epigenetic clock studies

The first 2018 epigenetic clock human study was from Finland:

“We evaluated the association between maternal antenatal depression and a novel biomarker of aging at birth, namely epigenetic gestational age (GA) based on fetal cord blood methylation data. We also examined whether this biomarker prospectively predicts and mediates maternal effects on early childhood psychiatric problems.

Maternal history of depression diagnosed before pregnancy and greater antenatal depressive symptoms were associated with child’s lower epigenetic GA. Child’s lower epigenetic GA, in turn, prospectively predicted total and internalizing problems and partially mediated the effects of maternal antenatal depression on internalizing problems in boys.”


Listening to a podcast by one of the coauthors, although the researchers’ stated intent was to determine the etiology of the findings, I didn’t hear any efforts to study the parents in sufficient detail to be able to detect possible intergenerational and transgenerational epigenetic inheritance causes and effects. There were the usual “associated with” and “it could be this, it could be that” hedges, which were also indicators of the limited methods employed toward the study’s limited design.

Why was an opportunity missed to advance human research in this area? Are researchers satisfied with non-causal individual differences non-explanations instead of making efforts in areas that may produce etiological findings?

https://www.jaacap.org/article/S0890-8567(18)30107-2/pdf “The Epigenetic Clock at Birth: Associations With Maternal Antenatal Depression and Child Psychiatric Problems” (not freely available)


The second 2018 epigenetic clock human study was from Alabama:

“We estimated measures of epigenetic age acceleration in 830 Caucasian participants from the Genetics Of Lipid Lowering Drugs and diet Network (GOLDN) considering two epigenetic age calculations.

Both DNA methylation age estimates were highly correlated with chronological age. We found that the Horvath and Hannum measures of epigenetic age acceleration were moderately correlated.

The Horvath age acceleration measure exhibited marginal associations with increased postprandial [after eating a meal] HDL [high-density lipoprotein], increased postprandial total cholesterol, and decreased soluble interleukin 2 receptor subunit alpha (IL2sRα). The Hannum measure of epigenetic age acceleration was inversely associated with fasting HDL and positively associated with postprandial TG [triglyceride], interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor alpha (TNFα).

Overall, the observed effect sizes were small.


https://clinicalepigeneticsjournal.biomedcentral.com/track/pdf/10.1186/s13148-018-0481-4 “Metabolic and inflammatory biomarkers are associated with epigenetic aging acceleration estimates in the GOLDN study”


The third 2018 epigenetic clock human study was a meta-analysis of cohorts from the UK, Italy, Sweden, and Scotland:

“The trajectories of Δage showed a declining trend in almost all of the cohorts with adult sample collections. This indicates that epigenetic age increases at a slower rate than chronological age, especially in the oldest population.

Some of the effect is likely driven by survival bias, where healthy individuals are those maintained within a longitudinal study, although other factors like underlying training population for the respective clocks may also have influenced this trend. It may also be possible that there is a ceiling effect for Δage whereby epigenetic clock estimates plateau.”

https://academic.oup.com/biomedgerontology/advance-article/doi/10.1093/gerona/gly060/4944478 “Tracking the Epigenetic Clock Across the Human Life Course: A Meta-analysis of Longitudinal Cohort Data”

Resiliency in stress responses

This 2018 US Veterans Administration review subject was resiliency and stress responses:

Neurobiological and behavioral responses to stress are highly variable. Exposure to a similar stressor can lead to heterogeneous outcomes — manifesting psychopathology in one individual, but having minimal effect, or even enhancing resilience, in another.

We highlight aspects of stress response modulation related to early life development and epigenetics, selected neurobiological and neurochemical systems, and a number of emotional, cognitive, psychosocial, and behavioral factors important in resilience.”

The review cited studies I’ve previously curated:


There were two things I didn’t understand about this review. The first was why the paper isn’t freely available. It’s completely paid for by the US taxpayer, and no copyright is claimed. I recommend contacting the authors for a copy.

The second was why the VA hasn’t participated in either animal or human follow-on studies to the 2015 Northwestern University GABAergic mechanisms regulated by miR-33 encode state-dependent fear. That study’s relevance to PTSD, this review’s subject, and the VA’s mission is too important to ignore. For example:

“Fear-inducing memories can be state dependent, meaning that they can best be retrieved if the brain states at encoding and retrieval are similar.

“It’s difficult for therapists to help these patients,” Radulovic said, “because the patients themselves can’t remember their traumatic experiences that are the root cause of their symptoms.”

The findings imply that in response to traumatic stress, some individuals, instead of activating the glutamate system to store memories, activate the extra-synaptic GABA system and form inaccessible traumatic memories.”

I curated the research in A study that provided evidence for basic principles of Primal Therapy. These researchers have published several papers since then. Here are the abstracts from three of them:

Experimental Methods for Functional Studies of microRNAs in Animal Models of Psychiatric Disorders

“Pharmacological treatments for psychiatric illnesses are often unsuccessful. This is largely due to the poor understanding of the molecular mechanisms underlying these disorders. We are particularly interested in elucidating the mechanism of affective disorders rooted in traumatic experiences.

To date, the research of mental disorders in general has focused on the causal role of individual genes and proteins, an approach that is inconsistent with the proposed polygenetic nature of these disorders. We recently took an alternative direction, by establishing the role of miRNAs in the coding of stress-related, fear-provoking memories.

Here we describe in detail our work on the role of miR-33 in state-dependent learning, a process implicated in dissociative amnesia, wherein memories formed in a certain brain state can best be retrieved if the brain is in the same state. We present the specific experimental approaches we apply to study the role of miRNAs in this model and demonstrate that miR-33 regulates the susceptibility to state-dependent learning induced by inhibitory neurotransmission.”

Neurobiological mechanisms of state-dependent learning

“State-dependent learning (SDL) is a phenomenon relating to information storage and retrieval restricted to discrete states. While extensively studied using psychopharmacological approaches, SDL has not been subjected to rigorous neuroscientific study.

Here we present an overview of approaches historically used to induce SDL, and highlight some of the known neurobiological mechanisms, in particular those related to inhibitory neurotransmission and its regulation by microRNAs (miR).

We also propose novel cellular and circuit mechanisms as contributing factors. Lastly, we discuss the implications of advancing our knowledge on SDL, both for most fundamental processes of learning and memory as well as for development and maintenance of psychopathology.”

Neurobiological correlates of state-dependent context fear

“Retrieval of fear memories can be state-dependent, meaning that they are best retrieved if the brain states at encoding and retrieval are similar. Such states can be induced by activating extrasynaptic γ-aminobutyric acid type A receptors (GABAAR) with the broad α-subunit activator gaboxadol. However, the circuit mechanisms and specific subunits underlying gaboxadol’s effects are not well understood.

Here we show that gaboxadol induces profound changes of local and network oscillatory activity, indicative of discoordinated hippocampal-cortical activity, that were accompanied by robust and long-lasting state-dependent conditioned fear. Episodic memories typically are hippocampus-dependent for a limited period after learning, but become cortex-dependent with the passage of time.

In contrast, state-dependent memories continued to rely on hippocampal GABAergic mechanisms for memory retrieval. Pharmacological approaches with α- subunit-specific agonists targeting the hippocampus implicated the prototypic extrasynaptic subunits (α4) as the mediator of state-dependent conditioned fear.

Together, our findings suggest that continued dependence on hippocampal rather than cortical mechanisms could be an important feature of state-dependent memories that contributes to their conditional retrieval.”


Here’s an independent 2017 Netherlands/UC San Diego review that should bring these researchers’ efforts to the VA’s attention:

MicroRNAs in Post-traumatic Stress Disorder

“Post-traumatic stress disorder (PTSD) is a psychiatric disorder that can develop following exposure to or witnessing of a (potentially) threatening event. A critical issue is to pinpoint the (neuro)biological mechanisms underlying the susceptibility to stress-related disorder such as PTSD, which develops in the minority of ~15% of individuals exposed to trauma.

Over the last few years, a first wave of epigenetic studies has been performed in an attempt to identify the molecular underpinnings of the long-lasting behavioral and mental effects of trauma exposure. The potential roles of non-coding RNAs (ncRNAs) such as microRNAs (miRNAs) in moderating or mediating the impact of severe stress and trauma are increasingly gaining attention. To date, most studies focusing on the roles of miRNAs in PTSD have, however, been completed in animals, using cross-sectional study designs and focusing almost exclusively on subjects with susceptible phenotypes.

Therefore, there is a strong need for new research comprising translational and cross-species approaches that use longitudinal designs for studying trajectories of change contrasting susceptible and resilient subjects. The present review offers a comprehensive overview of available studies of miRNAs in PTSD and discusses the current challenges, pitfalls, and future perspectives of this field.”

Here’s a 2017 Netherlands human study that similarly merits the US Veterans Administration’s attention:

Circulating miRNA associated with posttraumatic stress disorder in a cohort of military combat veterans

“Posttraumatic stress disorder (PTSD) affects many returning combat veterans, but underlying biological mechanisms remain unclear. In order to compare circulating micro RNA (miRNA) of combat veterans with and without PTSD, peripheral blood from 24 subjects was collected following deployment, and isolated miRNA was sequenced.

PTSD was associated with 8 differentially expressed miRNA. Pathway analysis shows that PTSD is related to the axon guidance and Wnt signaling pathways, which work together to support neuronal development through regulation of growth cones. PTSD is associated with miRNAs that regulate biological functions including neuronal activities, suggesting that they play a role in PTSD symptomatology.”


See the below comments for reasons why I downgraded this review’s rating.

https://link.springer.com/article/10.1007/s11920-018-0887-x “Stress Response Modulation Underlying the Psychobiology of Resilience” (not freely available)