Evolutionary perspectives on neurodevelopmental disorders

We discuss evolutionary perspectives on two neurodevelopmental disorders: attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD). Both have a genetic background, and we explore why these genes may have survived the process of natural selection. We draw on the concept of evolutionary mismatch, in which a trait that may have conferred advantages in the past can become disadvantageous when the environment changes. We also describe the non-genetic influences on these conditions. We point out that children with neurodevelopmental conditions are more likely to suffer maltreatment, so it is important to consider both the genes and the environment in which children have grown up. In hunter-gatherer societies, ADHD may have favoured risk-taking, which may explain why it has survived. The contemporary model of schooling, in which children are expected to sit still for many hours a day, does not favour this. Understanding ADHD in terms of an evolutionary mismatch therefore raises ethical issues regarding both medication and the school environment. ASDs are far more heterogeneous and are characterised by high heritability and low reproductive success. At the severe end of the spectrum, ASD is highly disadvantageous and often co-occurs with intellectual disability. On the other hand, high-functioning ASD may have been adaptive in our evolutionary past in terms of the potential for the development of specialist skills and can still be so today in the right environment

Antidepressants may lead to a decrease in niacin and NAD in patients with poor dietary intake

The term niacin is the generic name for the two compounds nicotinic acid and nicotinamide, the major dietary precursors for two important coenzymes, nicotinamide adenine dinucleotide (NAD) and its phosphorylated form, NADP. Niacin is important for the maintenance of cellular integrity and energy production and is involved in more than 500 intracellular reactions. Deficiencies of niacin may contribute to neuropsychiatric and neurodegenerative disorders. Patients who develop nutritional deficiencies as a result of poor dietary intake, could potentially suffer from niacin deficiency and NAD depletion. However, de novo synthesis of niacin and NAD in the kynurenine pathway of tryptophan metabolism may compensate for impaired dietary intake. The rate of synthesis of NAD and niacin from tryptophan oxidation depends on the induction of the enzyme indoleamine 2,3- dioxygenase (IDO) by pro-inflammatory cytokines such as interferon-gamma. Niacin synthesis is not limited by a decrease in tryptophan and excessive IDO activity may therefore lead to a decline in tryptophan levels. Antidepressants have an anti-inflammatory effect, including reduction of interferon-gamma and therefore inhibition of IDO, the ratelimiting enzyme of the kynurenine pathway. In theory, this could account for increased serotonin as more tryptophan becomes available for serotonin synthesis. However, the downside may be that less NAD and niacin are synthesised downstream, which could exacerbate common psychiatric problems. It is our hypothesis that patients with poor dietary intake, who are treated with antidepressants, are at risk of developing niacin/NAD deficiency with possible development of associated neuropsychiatric symptoms. We therefore propose that niacin supplementation be considered in patients with inadequate diets who are treated with antidepressants. We believe that if this does not happen, a subclinical niacin deficiency may result, which would be difficult to detect as it would cause the same symptoms of the original illness (e.g. depression). Niacin deficiency should be considered and ruled out in all patients with treatment-resistant depression, who have a poor response to antidepressants. This is potentially a cost-effective and easy intervention, which could be examined in a randomized controlled trial.http://www.elsevier.com/locate/mehy2016-03-31hb201

How evolution can help us understand child development and behaviour

The traditional disease model, still dominant in psychiatry, is less than ideal for making sense of psychological issues such as the effects of early childhood experiences on development. We argue that a model based on evolutionary thinking can deepen understanding and aid clinical practice by showing how behaviours, bodily responses and psychological beliefs tend to develop for ‘adaptive’ reasons, even when these ways of being might on first appearance seem pathological. Such understanding has implications for treatment. It also challenges the genetic determinist model, by showing that developmental pathways have evolved to be responsive to the physical and social environment in which the individual matures. Thought can now be given to how biological or psychological treatments – and changing a child’s environment – can foster well-being. Evolutionary thinking has major implications for how we think about psychopathology and for targeting the optimum sites, levels and timings for intervention

How evolutionary science can help us understand vaccine refusal in the COVID-19 pandemic

Unvaccinated people have a mortality rate from COVID-19 that is 32-fold that of fully vaccinated people. Yet, in the UK, more than 4% of adults have not accepted a vaccine to protect them against COVID-19 and at the time of writing only 73% of people were fully vaccinated. Psychological and societal factors underlying vaccine hesitation or refusal are complex. In this paper, we use evolutionary science to help explain how vaccine refusal can be the result of an historic adaptation to protect against the repetition of past trauma, including, for many, that of systemic racism and/or deprivation, and misguided attempt to preserve fertility. We discuss some resulting cognitive biases and conclude with recommendations for practice

Digital health promotion: promise and peril

The World Health Organization defines health promotion as process of enabling people to increase control over their health and its determinants, and thereby improve their health. As the world transitions into the information age, incorporating digital technologies into health promotion is becoming commonplace. This article discusses current applications of digital health promotion (DHP) and addresses its potential benefits, challenges, as well as how differences in cultures, governance models and digital readiness across the globe will shape the implementation of DHP differently in each society. The benefits include expanding access to health information and health promoting services, lowering scaling up costs, personalizing health advice and real-time ‘nudging’ toward healthier options. Key challenges would involve privacy control, appropriate use of data including secondary usage beyond the original intention, defining the limits of ‘nudging’ and the right of free choice, and ensuring widespread accessibility and affordability to minimize the exacerbation of social inequities. Finally, we discuss the enabling factors for successful DHP implementation, suggesting measures that should be taken at both individual and system levels. At the individual level, we explore the factors necessary to access and benefit from DHP meaningfully; at the system level, we examine the infrastructure required to provide wide access, establish trust among users and enable sustainability of behavioral changes.http://heapro.oxfordjournals.orghj2022Speech-Language Pathology and Audiolog

An in vitro and in vivo study on the properties of hollow polycaprolactone cell-delivery particles

The field of dermal fillers is evolving rapidly and numerous products are currently on the market. Biodegradable polymers such as polycaprolactone (PCL) have been found to be compatible with several body tissues, and this makes them an ideal material for dermal filling purposes. Hollow PCL spheres were developed by the Council for Scientific and Industrial Research (CSIR) to serve both as an anchor point and a ªtissue harbourº for cells. Particles were tested for cytotoxicity and cell adherence using mouse embryo fibroblasts (MEF). MEFs adhered to the particles and no significant toxic effects were observed based on morphology, cell growth, cell viability and cell cycle analysis, suggesting that the particles are suitable candidates for cell delivery systems in an in vivo setting. The objective of providing a ªtissue harbourº was however not realized, as cells did not preferentially migrate into the ported particles. In vivo studies were conducted in BALB/c mice into whom particles were introduced at the level of the hypodermis. Mice injected with PCL particles (ported and nonported; with or without MEFs) showed evidence of local inflammation and increased adipogenesis at the site of injection, as well as a systemic inflammatory response. These effects were also observed in mice that received apparently inert (polystyrene) particles. Ported PCL particles can therefore act as a cell delivery system and through their ability to induce adipogenesis, may also serve as a dermal bulking agent.S1 File. Figure A: Chronic inflammation in the test animals over the trial period. Figure B: Acute inflammation in the test animals over the trial period. Figure C: Tissue necrosis in the test animals over the trial period. Figure D: Fibrosis in the test animals over the trial period. Figure E: Granulomatous/foreign body response in the test animals over the trial period. Figure F: Representative TEMs of skin biopsies of particles group (A) and particles+MEFs group (B) in the in vivo experiment injecting particles+MEFs. Particles could be identified in skin biopsies of both the particles and particles+MEFs groups. The aim of the TEM investigation was to determine if any cells could be detected inside the particles. No cells were present inside the particles in either group. These results reflect the conclusion that was made after the light microscopy study, indicating that cells did not migrate into the ported PCL particles. Bar in A = 5μm and in B = 10μm.S2 File. In vitro and in vivo data. Table A: Groups of rats used in the biotoxicity trial. Table B: Observations on mice in the in vivo experiment assessing the effect of ported PCL particles and cells. Table C: Statistical comparisons preformed between the various white blood cell types assessed from blood smears of experimental mice injected with ported PCL particles with or without MEFs. Table D: Schedule of the in vivo experiment assessing the effect of ported and non-ported PCL as well as polystyrene (PS) particles. Table E: Overview of the animals, tests and procedures performed in the in vivo experiment assessing the effect of ported and non-ported PCL as well as polystyrene (PS) particles in BALB/c mice.S3 File. All data underlying the findings of the study.The Council for Scientific and Industrial Research, South Africa, by the Institute for Cellular and Molecular Medicine of the University of Pretoria and by the South African Medical Research Council (Flagship Award SAMRC-RFA-UFSP-01-2013/ STEM CELLS and the SAMRC Extramural Unit for Stem Cell Research and Therapy).http://www.plosone.orgam2019ImmunologyPhysiolog

The DECRYPT trial: Study protocol for a phase II randomised controlled trial of cognitive therapy for post-traumatic stress disorder (PTSD) in youth exposed to multiple traumatic stressors

Background: Post-traumatic stress disorder (PTSD) is a distressing and disabling condition that affects significant numbers of children and adolescents. Youth exposed to multiple traumas (eg, abuse, domestic violence) are at particular risk of developing PTSD. Cognitive therapy for PTSD (CT-PTSD), derived from adult work, is a theoretically informed, disorder-specific form of trauma-focused cognitive–behavioural therapy. While efficacious for child and adolescent single-event trauma samples, its effectiveness in routine settings with more complex, multiple trauma-exposed youth has not been established. The Delivery of Cognitive Therapy for Young People after Trauma randomised controlled trial (RCT) examines the effectiveness of CT-PTSD for treating PTSD following multiple trauma exposure in children and young people in comparison with treatment as usual (TAU). Methods/design: This protocol describes a two-arm, patient-level, single blind, superiority RCT comparing CT-PTSD (n=60) with TAU (n=60) in children and young people aged 8–17 years with a diagnosis of PTSD following multiple trauma exposure. The primary outcome is PTSD severity assessed using the Children’s Revised Impact of Event Scale (8-item version) at post-treatment (ie, approximately 5 months post-randomisation). Secondary outcomes include structured interview assessment for PTSD, complex PTSD symptoms, depression and anxiety, overall functioning and parent-rated mental health. Mid-treatment and 11-month and 29-month post-randomisation assessments will also be completed. Process–outcome evaluation will consider which mechanisms underpin or moderate recovery. Qualitative interviews with the young people, their families and their therapists will be undertaken. Cost-effectiveness of CT-PTSD relative to TAU will be also be assessed. Ethics and dissemination: This trial protocol has been approved by a UK Health Research Authority Research Ethics Committee (East of England–Cambridge South, 16/EE/0233). Findings will be disseminated broadly via peer-reviewed empirical journal articles, conference presentations and clinical workshops. Trial registration: ISRCTN12077707. Registered 24 October 2016 (http://www.isrctn.com/ISRCTN12077707). Trial recruitment commenced on 1 February 2017. It is anticipated that recruitment will continue until June 2021, with 11-month assessments being concluded in May 2022

Editorial Perspective: What can we learn from hunter‐gatherers about children's mental health? An evolutionary perspective

Humans lived as hunter‐gatherers for more than 95% of our evolutionary history, thus studying contemporary hunter‐gatherer populations offers insight into the conditions children may be psychologically adapted to. Here, we contrast hunter‐gatherer childhoods with those of WEIRD (Western Educated Industrialised Rich Democratic) societies and consider the implications for children's mental health. Hunter‐gatherer infants receive continuous physical contact and more sensitive and responsive caregiving than is typical of WEIRD societies, due to the extensive involvement of alloparents (non‐parental caregivers) who generally provide 40–50% of their care. Alongside positive attachment outcomes, alloparenting likely reduces the harms of family adversity and risk of abuse/neglect. From late infancy, hunter‐gatherers spend their time in mixed‐age ‘playgroups’ where they learn via active play and exploration without adult supervision. This contrasts with WEIRD norms surrounding the need for adult supervision of children, as well as with the passive teacher‐led classrooms, which could potentially lead to suboptimal learning outcomes and pose difficulties to children with ADHD. Based on this preliminary comparison, we consider practical solutions to potential harms arising from discordance between what children are adapted to and exposed to. These include infant massage and babywearing; increased sibling and extra‐familial involvement in childcare; and educational adjustments

What Can We Learn from Hunter-Gatherers about Children’s Mental Health? An Evolutionary Perspective

Humans lived as hunter-gatherers for more than 95% of our evolutionary history, thus studying contemporary hunter-gatherer populations offers insight into the conditions children may be psychologically adapted to. Here, we contrast hunter-gatherer childhoods with those of WEIRD (Western Educated Industrialised Rich Democratic) societies, and consider the implications for children’s mental health. Hunter-gatherer infants receive continuous physical contact, and more sensitive and responsive caregiving than is typical of WEIRD societies, due to the extensive involvement of alloparents (non-parental caregivers) who generally provide 40-50% of their care. Alongside positive attachment outcomes, alloparenting likely reduces the harms of family adversity and risk of abuse/neglect. From late infancy, hunter-gatherers spend their time in mixed-age ‘playgroups’ where they learn via active play and exploration without adult supervision. This contrasts with WEIRD norms surrounding the need for adult supervision of children, as well as with the passive teacher-led classrooms, which could potentially lead to suboptimal learning outcomes and pose difficulties to children with ADHD. Based on this preliminary comparison, we consider practical solutions to potential harms arising from discordance between what children are adapted to and exposed to. These include infant massage and babywearing; increased sibling and extra-familial involvement in childcare; and educational adjustments