Evolutionary psychiatry: foundations, progress and challenges

Understanding the Emergence of Schizophrenia in the Light of Human Evolution: New Perspectives in Genetics

Schizophrenia is a frequent and disabling disease. The persistence of the disorder despite its harmful consequences represents an evolutionary paradox. Based on recent discoveries in genetics, scientists have formulated the "price-to-pay" hypothesis: schizophrenia would be intimately related to human evolution, particularly to brain development and human-specific higher cognitive functions. The objective of the present work is to question scientific literature about the relationship between schizophrenia and human evolution from a genetic point of view. In the last two decades, research investigated the association between schizophrenia and a few genetic evolutionary markers: Human accelerated regions, segmental duplications, and highly repetitive DNA such as the Olduvai domain. Other studies focused on the action of natural selection on schizophrenia-associated genetic variants, also thanks to the complete sequencing of archaic hominins' genomes (Neanderthal, Denisova). Results suggested that a connection between human evolution and schizophrenia may exist; nonetheless, much research is still needed, and it is possible that a definitive answer to the evolutionary paradox of schizophrenia will never be found.

Differences in Emotional Awareness Moderate Cytokine-Symptom Associations Among Breast Cancer Survivors

Cancer survivors have elevated levels of proinflammatory cytokines, which could be associated with cancer-related symptoms. Given that proinflammatory cytokines heighten negative affect by directly affecting the brain, we explored these direct associations and whether differences in levels of emotional awareness moderate the associations between proinflammatory cytokines and cancer-related symptoms. This cross-sectional, secondary analysis of baseline data was collected from 162 female breast cancer survivors (aged 36-70 years), who were enrolled 6 ± 4 months after completing cancer treatment. We tested cytokines in serum (IL-1β, IL-6, IL-8, TNF-α, IL-4, IL-10, and TGF-β) and assessed depression, cancer-related fatigue, pain intensity, and pain interference. Emotional awareness was assessed using a performance measure, the Levels of Emotional Awareness Scale. In participants with high but not average or low levels of emotional awareness, positive associations were found for IL-1β, IL-6, and TNF-α with depression and between IL-6 and TNF-α with pain intensity. In addition, IL-6 had a positive association with pain intensity at average levels of emotional awareness. These results suggest that women with high or in some cases average, but not low, emotional awareness reported depression and pain as being positively associated with their cytokine levels. By using emotional awareness as a cognitive resource to promote emotion regulation and distress transformation, interventions may be able to counteract heightened sensitivity to the mood-altering effects of cytokines.

The relevance of the evolutionary approach for understanding health and disease of the human body and mind

Ultimate and proximate levels of analysis offer synergistic explanations can improve the search for causes of disease and their cures. Here we review how several principles of evolutionary biology such as historical contingencies, mismatches, trade-offs, sexual selection and genomic conflict are applied to problems in medicine and psychiatry. The application of evolutionary principles to many other domains of medicine, among them mental disorders, have not received the same reception from preclinical and clinical researchers. The lack of a well-coordinated interdisciplinarity may be one reason for the slow application of evolutionary principles to biomedicine and psychiatry. This is exemplified by the case of ethopharmacology, an evolutionary approach to psychopharmacology strongly proposed and applied by ethologists but apparently unknown to many evolutionary minded scholars. Another reason has to do with the lack of efforts from many medical schools to integrate evolution and its principles in their curriculum studiorum. Interestingly, this Darwinian approach is generating an important evolutionary epistemology for the study of body and human mind health and diseases.

ADHD and ASD are Normal Biological Variations as part of Human Evolution and are not "Disorders"

Recent developments driven by people with attention-deficit hyperactivity disorder (ADHD) and/or autism spectrum disorder (ASD) have highlighted that far from being disorders, ADHD and/or ASD can be seen as natural variations in neurodevelopment. The neurodiversity movement acknowledges that people with ADHD and/or ASD have specific strengths, that can help them outperform neurotypical individuals in certain situations and that these conditions should therefore not be seen as disorders. This view is supported by evolutionary science, which can be used as a framework to understand ADHD and/or ASD as natural variations that were not eliminated by natural selection due to their benefit to the individual and group in certain situations. The evolutionary perspective supports neurodiversity as relevant and important in helping our species thrive.

The Thoughtful program: a randomized controlled study of a mentalization-based mental health education intervention in a psychiatric outpatient population

BACKGROUND

P-factor and mentalizing theory and research set perspectives for transdiagnostic psychiatric treatments.

AIMS

To test the effects of a low-cost mentalization-based health education program (the Thoughtful program) in an unselected waiting list population, from a psychiatric outpatient clinic in North Norway.

METHODS

Waiting list patients were randomized (1:1 allocation): 79 patients in the control group were offered standard individual assessment and treatment. Seventy-nine patients in the intervention group were offered a one-day (six-hour) group-based Thoughtful course, plus individual assessment, and treatment.

RESULTS

During a 6-month follow-up period, the number of patients in active assessment and treatment was 66% higher in the control group than in the intervention group. Self-reported patient questionnaire scores on mentalizing, well-being and suicidal ideation scores showed no significant changes in the control group. In the intervention group, significant changes were reported: Mentalizing scores improved by 72% and well-being scores improved by 55%. Suicidal ideation scores were not significantly changed. No adverse effects were registered.

LIMITATIONS

The results from this study should be interpreted with caution because of a small population size and low questionnaire response rate. The follow up period was limited to 6 months. Transfer of program information from intervention group patients to control group patients could not be guaranteed. It may be considered a limitation that diagnostic pattern analysis was not included in the study.

CONCLUSIONS

A low-cost transdiagnostic mentalization-based educational program in an outpatient psychiatry clinic may improve patient mentalizing and wellbeing without adverse effects and reduce the use of hospital services.

Attachment-informed mental healthcare systems as 'organisational caregivers': ideas for the future

Over the past 50 years, mental health services have evolved significantly, influenced by shifts in theoretical and practical approaches to mental disorders. Key among these changes are the biopsychosocial and recovery models, which highlight resilience and quality of life in treatment. However, traditional psychiatry has often struggled to embrace these changes because of reductionist perspectives that overlook psychosocial factors, resulting in fragmented care and reduced accessibility. Proposed solutions have faced implementation barriers in absence of a coherent theoretical framework. Here, we outline how attachment theory may offer a promising framework to drive systemic change in mental health by emphasising secure emotional bonds at both the organisational and individual level. Within an attachment-informed culture, services may act as 'organisational caregivers' that promote continuity of care, independence and stronger clinical relationships. In turn, this may foster more inclusive, responsive and resilient mental healthcare systems that prioritise patients' needs and empowerment.

How accurately can supervised machine learning model predict a targeted psychiatric disorder?

BACKGROUND

Hoarding disorder (HD) is characterized by a compulsion to collect belongings, and to experience significant distress when parting from them. HD is often misdiagnosed for several reasons. These include patient and family lack of recognition that it is a psychiatric disorder and professionals' lack of relevant expertise with it. This study evaluates the ability of a supervised machine learning (ML) model to match the diagnostic skills of psychiatrists when presented with equivalent information pertinent to symptoms of HD.

METHODS

Five hundred online participants were randomly recruited and completed the Hoarding Rating Scale-Self Report (HRS-SR) and the Generalized Anxiety Disorder 7-item (GAD-7) scale. Responses to the questionnaires were read by an ML model. Responses to the HRS-SR were then converted into anonymized, random-equivalent texts. Each of these individual texts was presented in random order to two experienced psychiatrists who were independently asked for a provisional diagnosis - e.g.; the presence or absence of HD. In case of disagreement between the two assessors, a third psychiatrist broke the tie. A decision tree classification model was employed to predict clinical HD using self-report data from two psychological tests, the HRS-SR and GAD-7. The target variable was whether a participant had clinical HD, while the predictive variables were the continuous scores from the HRS-SR and GAD-7 tests. The model's performance was evaluated using a confusion matrix, which compared the observed diagnoses with the predicted diagnoses to assess accuracy.

RESULTS

According to the psychiatrists, approximately 10% of the participants fulfilled DSM-5 diagnostic criteria for HD. 93% of the clinician-identified cases were identified by the ML model based on HRS-SR and GAD-7 scores. A decision tree plot model demonstrated that about 60% of the cases could be detected by the HRS-SR alone while the rest required a combination of HRS-SR and GAD-7 scores. ML evaluation metrics showed satisfactory performance, with a Matthews Correlation Coefficient of 55%; Area Under Curve (AUC), 79%; a Negative Predictive Value of 76%; and a False Negative Rate of 24%.

CONCLUSIONS

Study findings strongly suggest that ML can, in the future, play a significant role in the risk assessment of psychiatric disorders prior to face-to-face consultation. By using AI to scan big data questionnaire responses, wait time for seriously ill patients can be substantially cut, and prognoses substantially improved.

Evolution: the bridge between 'biological' and 'social' psychiatry

'Biological' and 'social' perspectives in psychiatry have exchanged dominance at different times in the history of our field and are sometimes erroneously viewed as being contrasting and mutually exclusive paradigms. We argue that the arbitrary 'biological/social' divide in psychiatry is misleading, unhelpful, and ultimately a false one. We propose that the evolutionary perspective provides a necessary framework and metatheory that can bridge this apparent schism in psychiatric thinking, providing novel and useful insights into how we can better assess, diagnose, and treat our patients.

Active Inference in Psychology and Psychiatry: Progress to Date?

The free energy principle is a formal theory of adaptive self-organising systems that emerged from statistical thermodynamics, machine learning and theoretical neuroscience and has since been translated into biologically plausible 'process theories' of cognition and behaviour, which fall under the banner of 'active inference'. Despite the promise this theory holds for theorising, research and practical applications in psychology and psychiatry, its impact on these disciplines has only now begun to bear fruit. The aim of this treatment is to consider the extent to which active inference has informed theoretical progress in psychology, before exploring its contributions to our understanding and treatment of psychopathology. Despite facing persistent translational obstacles, progress suggests that active inference has the potential to become a new paradigm that promises to unite psychology's subdisciplines, while readily incorporating the traditionally competing paradigms of evolutionary and developmental psychology. To date, however, progress towards this end has been slow. Meanwhile, the main outstanding question is whether this theory will make a positive difference through applications in clinical psychology, and its sister discipline of psychiatry.

The assessment of transdiagnostic dimensions of emotional disorders: Validation of the Multidimensional Emotional Disorders Inventory (MEDI) in adolescents with subthreshold anxiety and depression

BACKGROUND

The transdiagnostic approach to psychopathology has emerged as an alternative to traditional taxonomic approaches. The Multidimensional Emotional Disorders Inventory (MEDI) is a specifically designed self-report to measure the transdiagnostic dimensions proposed by Brown and Barlow (2009). This study aims to analyse the psychometric properties of the MEDI scores in adolescents with subthreshold anxiety and depression.

METHOD

The sample consisted of a total of 476 students. The mean age was 13.77 years (SD = 1.43) (range 10 to 18 years), 73.9 % were females. Several questionnaires assessing positive affect, negative affect, mental health difficulties, and quality of life were used.

RESULTS

The original 9-factor structure of the MEDI was confirmed with good fit indices. Satisfactory levels of internal consistency were observed in most of the MEDI scores using McDonald's Omega, ranging from 0.58 to 0.87. The MEDI dimensions were associated with psychopathology, positive affect, negative affect, and quality of life.

LIMITATIONS

Reliance on self-reported data, a cross-sectional design limiting temporal assessment, and a 73.9 % female gender imbalance.

CONCLUSION

The MEDI scores showed adequate psychometric properties among adolescents with subclinical emotional symptoms. The results found might have potential clinical implications for conceptualization, assessment, intervention, and prevention of emotional disorders at both clinical and research levels.

Mediation role of interpersonal problems between insecure attachment and eating disorder psychopathology

PURPOSE

Although insecure attachment and interpersonal problems have been acknowledged as risk and maintaining factors of eating disorders (EDs), the mediating role of interpersonal problems between attachment style and ED psychopathology has been poorly explored. The purpose of this study was to investigate the mediating role of interpersonal problems between insecure attachment and ED psychopathology.

METHODS

One-hundred-nine women with anorexia nervosa and 157 women with bulimia nervosa filled in the Eating Disorder Inventory-2 (EDI-2) and the Experiences in Close Relationships (ECR) revised scale to assess ED core symptoms and attachment styles, respectively. Interpersonal difficulties were evaluated by the Inventory of Interpersonal Problems (IIP-32). A mediator's path model was conducted with anxious and avoidant attachment subscores as independent variables, ED core symptoms as dependent variables and interpersonal difficulties as mediators. The diagnosis was entered in the model as a confounding factor.

RESULTS

The socially inhibited/avoidant interpersonal dimension was a mediator between avoidant attachment and the drive to thinness as well as between avoidant attachment and body dissatisfaction. An indirect connection was found between attachment-related anxiety and bulimic symptoms through the mediation of intrusive/needy score.

CONCLUSIONS

Social avoidance and intrusiveness mediate the relationships between avoidant and anxious attachment styles and ED psychopathology. These interpersonal problems may represent specific targets for psychotherapeutic treatments in individuals with EDs and insecure attachment.

LEVEL OF EVIDENCE

Level III: Evidence obtained from well-designed cohort or case-control analytic studies.

Perspective: the evolution of hormones and person perception-a quantitative genetic framework

Evolutionary biology provides a unifying theory for testing hypotheses about the relationship between hormones and person perception. Person perception usually receives attention from the perspective of sexual selection. However, because person perception is one trait in a suite regulated by hormones, univariate approaches are insufficient. In this Perspectives article, quantitative genetics is presented as an important but underutilized framework for testing evolutionary hypotheses within this literature. We note tacit assumptions within the current literature on psychiatric genetics, which imperil the interpretation of findings thus far. As regulators of a diverse manifold of traits, hormones mediate tradeoffs among an array of functions. Hormonal pleiotropy also provides the basis of correlational selection, a process whereby selection on one trait in a hormone-mediated suite generates selection on the others. This architecture provides the basis for conflicts between sexual and natural selection within hormone-mediated suites. Due to its role in person perception, psychiatric disorders, and reproductive physiology, the sex hormone estrogen is highlighted as an exemplar here. The implications of this framework for the evolution of person perception are discussed. Empirical quantification of selection on traits within hormone-mediated suites remains an important gap in this literature with great potential to illuminate the fundamental nature of psychiatric disorders.

A Descriptive Diagnosis or a Causal Explanation? Accuracy of Depictions of Depression on Authoritative Health Organization Websites

INTRODUCTION

Psychiatric diagnoses are descriptive in nature, but the lay public commonly misconceives them as causal explanations. It is not known whether this logical error, a form of circular reasoning, can sometimes be mistakenly reinforced by health authorities themselves. In this study, we investigated the prevalence of misleading causal descriptions of depression in the information provided by authoritative mental health organizations on widely accessed internet sites.

METHODS

We searched for popular websites managed by leading mental health organizations and conducted a content analysis to evaluate whether they presented depression accurately as a description of symptoms, or inaccurately as a causal explanation.

RESULTS

Most websites used language that inaccurately described depression as a causal explanation to depressive symptoms.

CONCLUSION

Leading professional medical and psychiatric organizations commonly confound depression, a descriptive diagnostic label, with a causal explanation on their most prominently accessed informational websites. We argue that the scientifically inaccurate causal language in depictions of psychiatric diagnoses is potentially harmful because it leads the public to misunderstand the nature of mental health problems. Mental health authorities providing psychoeducation should clearly state that psychiatric diagnoses are purely descriptive to avoid misleading the public.

Philosophy of psychiatry: theoretical advances and clinical implications

Work at the intersection of philosophy and psychiatry has an extensive and influential history, and has received increased attention recently, with the emergence of professional associations and a growing literature. In this paper, we review key advances in work on philosophy and psychiatry, and their related clinical implications. First, in understanding and categorizing mental disorder, both naturalist and normativist considerations are now viewed as important - psychiatric constructs necessitate a consideration of both facts and values. At a conceptual level, this integrative view encourages moving away from strict scientism to soft naturalism, while in clinical practice this facilitates both evidence-based and values-based mental health care. Second, in considering the nature of psychiatric science, there is now increasing emphasis on a pluralist approach, including ontological, explanatory and value pluralism. Conceptually, a pluralist approach acknowledges the multi-level causal interactions that give rise to psychopathology, while clinically it emphasizes the importance of a broad range of "difference-makers", as well as a consideration of "lived experience" in both research and practice. Third, in considering a range of questions about the brain-mind, and how both somatic and psychic factors contribute to the development and maintenance of mental disorders, conceptual and empirical work on embodied cognition provides an increasingly valuable approach. Viewing the brain-mind as embodied, embedded and enactive offers a conceptual approach to the mind-body problem that facilitates the clinical integration of advances in both cognitive-affective neuroscience and phenomenological psychopathology.

An Evolutionary Perspective on the DSM-5 Alternative Model for Personality Disorders

Recent work has nested the Alternative Model for Personality Disorders (AMPD) within several theoretical paradigms of personality and clinical psychology (e.g., multivariate, psychodynamic). This has both spurred on additional research and aided in practical application. Connecting the model to other theoretical heuristics may lead to further advances. One candidate for such a theory is that of evolutionary psychology, which attempts to provide explanations of human behavior (including personality traits) rooted in adaptation. In this article, we review and integrate the theoretical and empirical literature on the AMPD and evolutionary psychology, providing a synthesis of the two models in the hope of furthering the research and application of both.

Current perspectives on perinatal mental health and neurobehavioral development: focus on regulation, coregulation and self-regulation

PURPOSE OF REVIEW

Perinatal mental health research provides an important perspective on neurobehavioral development. Here, we aim to review the association of maternal perinatal health with offspring neurodevelopment, providing an update on (self-)regulation problems, hypothesized mechanistic pathways, progress and challenges, and implications for mental health.

RECENT FINDINGS

(1) Meta-analyses confirm that maternal perinatal mental distress is associated with (self-)regulation problems which constitute cognitive, behavioral, and affective social-emotional problems, while exposure to positive parental mental health has a positive impact. However, effect sizes are small. (2) Hypothesized mechanistic pathways underlying this association are complex. Interactive and compensatory mechanisms across developmental time are neglected topics. (3) Progress has been made in multiexposure studies. However, challenges remain and these are shared by clinical, translational and public health sciences. (4) From a mental healthcare perspective, a multidisciplinary and system level approach employing developmentally-sensitive measures and timely treatment of (self-)regulation and coregulation problems in a dyadic caregiver-child and family level approach seems needed. The existing evidence-base is sparse.

SUMMARY

During the perinatal period, addressing vulnerable contexts and building resilient systems may promote neurobehavioral development. A pluralistic approach to research, taking a multidisciplinary approach to theoretical models and empirical investigation needs to be fostered.

Evolutionary perspectives on substance and behavioural addictions: Distinct and shared pathways to understanding, prediction and prevention

Addiction poses significant social, health, and criminal issues. Its moderate heritability and early-life impact, affecting reproductive success, poses an evolutionary paradox: why are humans predisposed to addictive behaviours? This paper reviews biological and psychological mechanisms of substance and behavioural addictions, exploring evolutionary explanations for the origin and function of relevant systems. Ancestrally, addiction-related systems promoted fitness through reward-seeking, and possibly self-medication. Today, psychoactive substances disrupt these systems, leading individuals to neglect essential life goals for immediate satisfaction. Behavioural addictions (e.g. video games, social media) often emulate ancestrally beneficial behaviours, making them appealing yet often irrelevant to contemporary success. Evolutionary insights have implications for how addiction is criminalised and stigmatised, propose novel avenues for interventions, anticipate new sources of addiction from emerging technologies such as AI. The emerging potential of glucagon-like peptide 1 (GLP-1) agonists targeting obesity suggest the satiation system may be a natural counter to overactivation of the reward system.

Anxiety Disorders: The Relationship between Insight and Metacognition

BACKGROUND

The exploration of metacognition in relation to anxiety has received considerable attention in recent decades. Research indicates that it plays a role in the development and maintenance of anxiety disorders while also providing benefits, including the ability to assess situations, modify behaviors, and make informed decisions.

SUMMARY

We propose that having an awareness of a disorder, also known as insight, is related to metacognition in anxiety. This relationship stems from the ability it provides individuals to recognize their mental state through reflection on personal experiences. We discuss the impact of insight and metacognition on decision-making, treatment-seeking behaviors, and coping strategy selection.

KEY MESSAGES

Understanding the concept of insight in anxiety disorders, as compared to other mental disorders like psychosis, requires exploring its complexities while carefully considering the balance of harms and benefits. While the medicalization of symptoms in psychosis is widely regarded as clearly beneficial, evaluating the role of insight in anxiety disorders demands a more nuanced understanding. Gaining a fuller perspective on patients' beliefs can impact their behaviors and decision-making. Clinicians can achieve this by encouraging active self-reflection to increase awareness, which includes evaluating both severity and impact on daily functioning. This also involves expressing experiences and exploring attributions of anxiety. This practical approach enables clinicians to understand engagement and treatment-seeking behaviors, allowing them to tailor treatment plans and develop effective coping and management strategies. Ultimately, this knowledge promotes a deeper comprehension of insight into anxiety disorders.

Changing perspectives on autism: Overlapping contributions of evolutionary psychiatry and the neurodiversity movement

Perspectives on autism and psychiatric conditions are affected by a mix of scientific and social influences. Evolutionary psychiatry (EP) and the neurodiversity movement are emerging paradigms that reflect these distinct influences, with the former grounded in scientific theory and the latter driven by political and social principles. Despite their separate foundations, there is a significant overlap between EP and neurodiversity that has not been explored. Specifically, both paradigms reframe disorders as natural cognitive differences rather than disease; expand the concept of "normal" beyond that implied in modern psychiatry; focus on relative strengths; recognize that modern environments disadvantage certain individuals to cause functional impairment; emphasize cognitive variation being socially accommodated and integrated rather than treated or cured; and can help reduce stigmatization. However, in other ways, they are distinct and sometimes in conflict. EP emphasizes scientific explanation, defines "dysfunction" in objective terms, and differentiates heterogenous cases based on underlying causes (e.g. autism due to de novo genetic mutations). The neurodiversity movement emphasizes social action, removes barriers to inclusion, promotes inclusive language, and allows unrestricted identification as neurodivergent. By comparing and contrasting these two approaches, we find that EP can, to some extent, support the goals of neurodiversity. In particular, EP perspectives could be convincing to groups more responsive to scientific evidence and help achieve a middle ground between neurodiversity advocates and critics of the movement.

Advances in the understanding of the pathophysiology of schizophrenia and bipolar disorder through induced pluripotent stem cell models

The pathophysiology of schizophrenia and bipolar disorder involves a complex interaction between genetic and environmental factors that begins in the early stages of neurodevelopment. Recent advancements in the field of induced pluripotent stem cells (iPSCs) offer a promising tool for understanding the neurobiological alterations involved in these disorders and, potentially, for developing new treatment options. In this review, we summarize the results of iPSC-based research on schizophrenia and bipolar disorder, showing disturbances in neurodevelopmental processes, imbalance in glutamatergic-GABAergic transmission and neuromorphological alterations. The limitations of the reviewed literature are also highlighted, particularly the methodological heterogeneity of the studies, the limited number of studies developing iPSC models of both diseases simultaneously, and the lack of in-depth clinical characterization of the included samples. Further studies are needed to advance knowledge on the common and disease-specific pathophysiological features of schizophrenia and bipolar disorder and to promote the development of new treatment options.

Defensive responses: behaviour, the brain and the body

Most animals live under constant threat from predators, and predation has been a major selective force in shaping animal behaviour. Nevertheless, defence responses against predatory threats need to be balanced against other adaptive behaviours such as foraging, mating and recovering from infection. This behavioural balance in ethologically relevant contexts requires adequate integration of internal and external signals in a complex interplay between the brain and the body. Despite this complexity, research has often considered defensive behaviour as entirely mediated by the brain processing threat-related information obtained via perception of the external environment. However, accumulating evidence suggests that the endocrine, immune, gastrointestinal and reproductive systems have important roles in modulating behavioural responses to threat. In this Review, we focus on how predatory threat defence responses are shaped by threat imminence and review the circuitry between subcortical brain regions involved in mediating defensive behaviours. Then, we discuss the intersection of peripheral systems involved in internal states related to infection, hunger and mating with the neurocircuits that underlie defence responses against predatory threat. Through this process, we aim to elucidate the interconnections between the brain and body as an integrated network that facilitates appropriate defensive responses to threat and to discuss the implications for future behavioural research.