The new biology of obsessive-compulsive disorder: implications for evolutionary psychology

Seeking proxies for internal states (SPIS): Towards a novel model of obsessive-compulsive disorder

The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) proposes an account of OCD symptoms in terms of two core components: attenuation of access to internal states and seeking proxies for internal states. Specifically, the SPIS model posits that OCD is associated with difficulty in accessing various internal states, including feelings, preferences, memories, and even physiological states. This difficulty drives obsessive-compulsive individuals seek and rely on compensatory proxies, or substitutes, for their internal states. These proxies are perceived by the individual with OCD to be more easily discernible or less ambiguous compared to the internal states for which they substitute, and can take the form of fixed rules, rituals, or reliance on external sources of information. In the present article we first provide a detailed explanation of the SPIS model, and then review empirical studies that examined the model in a variety of domains, including bodily states, emotions, and decision-making. Next, we elaborate on the SPIS model's novel account of compulsive rituals, obsessions and doubt and relate them to extant theoretical accounts of OCD. To conclude, we highlight open questions that can guide future research and discuss the model's clinical implications.

The Psychopharmacology of Obsessive-Compulsive Disorder: A Preclinical Roadmap

This review evaluates current knowledge about obsessive-compulsive disorder (OCD), with the goal of providing a roadmap for future directions in research on the psychopharmacology of the disorder. It first addresses issues in the description and diagnosis of OCD, including the structure, measurement, and appropriate description of the disorder and issues of differential diagnosis. Current pharmacotherapies for OCD are then reviewed, including monotherapy with serotonin reuptake inhibitors and augmentation with antipsychotic medication and with psychologic treatment. Neuromodulatory therapies for OCD are also described, including psychosurgery, deep brain stimulation, and noninvasive brain stimulation. Psychotherapies for OCD are then reviewed, focusing on behavior therapy, including exposure and response prevention and cognitive therapy, and the efficacy of these interventions is discussed, touching on issues such as the timing of sessions, the adjunctive role of pharmacotherapy, and the underlying mechanisms. Next, current research on the neurobiology of OCD is examined, including work probing the role of various neurotransmitters and other endogenous processes and etiology as clues to the neurobiological fault that may underlie OCD. A new perspective on preclinical research is advanced, using the Research Domain Criteria to propose an adaptationist viewpoint that regards OCD as the dysfunction of a normal motivational system. A systems-design approach introduces the security motivation system (SMS) theory of OCD as a framework for research. Finally, a new perspective on psychopharmacological research for OCD is advanced, exploring three approaches: boosting infrastructure facilities of the brain, facilitating psychotherapeutic relearning, and targeting specific pathways of the SMS network to fix deficient SMS shut-down processes. SIGNIFICANCE STATEMENT: A significant proportion of patients with obsessive-compulsive disorder (OCD) do not achieve remission with current treatments, indicating the need for innovations in psychopharmacology for the disorder. OCD may be conceptualized as the dysfunction of a normal, special motivation system that evolved to manage the prospect of potential danger. This perspective, together with a wide-ranging review of the literature, suggests novel directions for psychopharmacological research, including boosting support systems of the brain, facilitating relearning that occurs in psychotherapy, and targeting specific pathways in the brain that provide deficient stopping processes in OCD.

Religion, evolution, and mental health: attachment theory and ETAS theory

This article reviews the historical origins of Attachment Theory and Evolutionary Threat Assessment Systems Theory (ETAS Theory), their evolutionary basis and their application in research on religion and mental health. Attachment Theory has been most commonly applied to religion and mental health in research on God as an attachment figure, which has shown that secure attachment to God is positively associated with psychological well-being. Its broader application to religion and mental health is comprehensively discussed by Kirkpatrick (2005). ETAS Theory explains why certain religious beliefs--including beliefs about God and life-after-death--should have an adverse association, an advantageous association, or no association at all with mental health. Moreover, it makes specific predictions to this effect, which have been confirmed, in part. The authors advocate the application of ETAS Theory in research on religion and mental health because it explains how religious and other beliefs related to the dangerousness of the world can directly affect psychiatric symptoms through their affects on specific brain structures.

Examining the acceptance of and resistance to evolutionary psychology

The field of psychology remains a divided one. Several different sub-disciplines (e.g., developmental, cognitive, behaviorism, social, etc.) form what could be a unified scientific area. However, there is no widely accepted theory of unification. Charles Darwin once theorized that evolutionary theory would change the foundation of psychology; but over the years, evolutionary psychology has been met with hostile resistance from some of the prominent psychologists within the other sub-disciplines. Yet in recent years, all of the divided sub-disciplines of psychology have been slowly implementing evolutionary principles into their literature and research. This slow integration of evolutionary psychology into the other sub-disciplines indicates the possibility of a unified psychology with evolution as its foundation. This paper briefly reviews the literature within each major sub-discipline of psychology to show their implementation of evolutionary psychological theories, indicating the possibility of evolutionary psychology becoming the unifying paradigm upon which the entire field of psychology can be based. A call for action to continue this process is also discussed.

Beliefs about God, psychiatric symptoms, and evolutionary psychiatry

The present study analyzed the association between specific beliefs about God and psychiatric symptoms among a representative sample of 1,306 U.S. adults. Three pairs of beliefs about God served as the independent variables: Close and Loving, Approving and Forgiving, and Creating and Judging. The dependent variables were measures of General Anxiety, Depression, Obsessive-Compulsion, Paranoid Ideation, Social Anxiety, and Somatization. As hypothesized, the strength of participants' belief in a Close and Loving God had a significant salutary association with overall psychiatric symptomology, and the strength of this association was significantly stronger than that of the other beliefs, which had little association with the psychiatric symptomology. The authors discuss the findings in the context of evolutionary psychiatry, and the relevance of Evolutionary Threat Assessment Systems Theory in research on religious beliefs.

The integrative function of the basal ganglia in instrumental conditioning

Recent research in instrumental conditioning has focused on the striatum, particularly the role of the dorsal striatum in the learning processes that contribute to instrumental performance in rats. This research has found evidence of what appear to be parallel, functionally and anatomically distinct circuits involving dorsomedial striatum (DMS) and dorsolateral striatum (DLS) that contribute to two independent instrumental learning processes. Evidence suggests that the formation of the critical action-outcome associations mediating goal-directed action are localized to the dorsomedial striatum, whereas the sensorimotor connections that control the performance of habitual actions are localized to the dorsolateral striatum. In addition to the dorsal striatum, these learning processes appear to engage distinct cortico-striatal networks and to be embedded in a complex of converging and partially segregated loops that constitute the cortico-striatal thalamo-cortical feedback circuit. As the entry point for the basal ganglia, cortical circuits involving the dorsal striatum are clearly in a position to control a variety of motor functions but, as recent studies of various neurodegenerative disorders have made clear, they are also involved in a number of cognitive and executive functions including action selection, planning, and decision-making.

Beliefs, mental health, and evolutionary threat assessment systems in the brain

This article reviews aspects of the literature on neuroscience, psychiatry, and cognitive and evolutionary psychology to illustrate how primitive brain mechanisms that evolved to assess environmental threats underlie psychiatric disorders, and how beliefs can affect psychiatric symptoms through these brain systems. Psychiatric theories are discussed that (a) link psychiatric disorders to threat assessment and (b) explain how the normal functioning of threat assessment systems can become pathological. Three brain structures that are consistently implicated in psychiatric symptomology also are involved in threat assessment and self-defense: the prefrontal cortex, the basal ganglia, and parts of the so-called limbic system. We propose that as these structures evolved over time they formed what we refer to as evolutionary threat assessment systems, which detect and assess potential threats of harm. Drawing on various psychological and psychiatric theories we propose how beliefs about the world can moderate psychiatric symptoms through their influence on evolutionary threat assessment systems.

Evolutionary theory, psychiatry, and psychopharmacology

Darwin's seminal publications in the nineteenth century laid the foundation for an evolutionary approach to psychology and psychiatry. Advances in 20th century evolutionary theory facilitated the development of evolutionary psychology and psychiatry as recognized areas of scientific investigation. In this century, advances in understanding the molecular basis of evolution, of the mind, and of psychopathology, offer the possibility of an integrated approach to understanding the proximal (psychobiological) and distal (evolutionary) mechanisms of interest to psychiatry and psychopharmacology. There is, for example, growing interest in the question of whether specific genetic variants mediate psychobiological processes that have evolutionary value in specific contexts, and of the implications of this for understanding the vulnerability to psychopathology and for considering the advantages and limitations of pharmacotherapy. The evolutionary value, and gene-environmental mediation, of early life programming is potentially a particularly rich area of investigation. Although evolutionary approaches to psychology and to medicine face important conceptual and methodological challenges, current work is increasingly sophisticated, and may prove to be an important foundational discipline for clinicians and researchers in psychiatry and psychopharmacology.

Sex differences in OCD symptomatology: An evolutionary perspective

Some evolutionists have construed obsessive-compulsive disorder (OCD) as the over-activation of warning systems in areas of evolutionary import. Using evolutionary theorizing, it is posited here that sex differences in the instantiation of specific obsessions and/or compulsions might correspond to sex-specific differences in the evolutionary import of the domain to which the particular symptom maps onto (e.g., mating versus parenting). Even in instances where no sex differences are found in the incidence of a particular obsession and/or compulsion (e.g., the extent to which men and women might suffer from intrusive thoughts), an evolutionary perspective might nonetheless propose that the contents of such thoughts map onto sex-specific adaptive concerns (e.g., social status and appearance-related concerns for men and women, respectively). An evolutionary approach might help not only in explaining sex differences in OCD phenomenology but also in elucidating within-sex manifestations of OCD symptoms (e.g., the shifting strength of contamination fears across a woman's menstrual cycle). The current evolutionary perspective not only provides an integrative ultimate-level meta-framework in understanding previously-found sex differences in OCD but also it permits OCD researchers to propose innovative hypotheses that otherwise might have been unlikely to be posited if one were to strictly focus on a proximate exploration of OCD. Cross-cultural clinical data, originating from a heterogeneous set of cultures and highlighting universal patterns of sex-specific OCD symptomatology, would provide a strong test of the posited hypotheses.

Psychoneuroimmunodermatology of atopic dermatitis: from empiric data to the evolutionary hypothesis

Atopic dermatitis is a pruritic skin disease affecting predominantly young people. There is evidence that psychologic stress constitutes an increased risk for atopy and influences the disease's clinical course. This risk is believed mediated by the effects of stress on neuroimmunoregulation, which in turn modulates the hypersensitivity response and involves immunoglobulin E-mediated inflammation, helper T-cell 2 predominance, and eosinophilia. This article examines theoretic perspectives and other behavioral dimensions, such as maternal caring behavior, infant response to stress, temperament, and the so-called "hygiene hypothesis." The Darwinian framework and the mental scenario are examined. These processes may be akin to the generation of antibodies by the immune system.

Could obsessive–compulsive disorder have originated as a group-selected adaptive trait in traditional societies?

Obsessive-compulsive disorder (OCD) possesses distinctive characteristics inviting evolutionary and anthropological explanations. A genetically based condition with low fecundity persisting through generations is paradoxical. The concept of group selection is an evolutionary principle capable of clarifying the perplexing epidemiology of OCD. Using a group-selection paradigm, the authors propose that OCD reflects an ancient form of behavioural specialization. The majority of compulsions such as checking, washing, counting, needing to confess, hoarding and requiring precision, all carry the potential to benefit society. Focussing primarily on hunting and gathering cultures, the potential evolutionary advantages of OCD are explored.

Obsessive-compulsive disorder as a disturbance of security motivation

The authors hypothesize that the symptoms of obsessive-compulsive disorder (OCD), despite their apparent nonrationality, have what might be termed an epistemic origin--that is, they stem from an inability to generate the normal "feeling of knowing" that would otherwise signal task completion and terminate the expression of a security motivational system. The authors compare their satiety-signal construct, which they term yedasentience, to various other senses of the feeling of knowing and indicate why OCD-like symptoms would stem from the abnormal absence of such a terminator emotion. In addition, they advance a tentative neuropsychological model to explain its underpinnings. The proposed model integrates many previous disparate observations and concepts about OCD and embeds it within the broader understanding of normal motivation.

The role of prelimbic cortex in instrumental conditioning

Numerous studies have implicated human and primate prefrontal cortex in the ability to hold and manipulate goal or outcome-related information in working memory to guide the performance of forthcoming actions. Here we report that cell-body lesions of prelimbic cortex impair the ability of rats to select an action based on previously encoded action-outcome associations. Rats were food deprived and trained to press two levers, one delivering food pellets and the other a sucrose solution. All rats acquired the lever-press response although the initial acquisition in the prelimbic rats was significantly slower than in sham controls. Furthermore, whereas in sham-lesioned rats, post-training devaluation of one of the two outcomes using a specific satiety procedure produced a selective reduction in performance on the lever that in training delivered the prefed outcome, prelimbic rats failed to show a selective devaluation effect and appeared to reduce performance on both levers non-selectively. Importantly, this impairment only emerged in extinction; in subsequent experiments it was found that, when a specific action-outcome association was cued either by presentation of the outcome itself or by presenting a stimulus previously paired with the outcome, rats demonstrated an ability to select the associated action. These results suggest that action-outcome encoding may be intact in prelimbic rats and that the lesion impaired their ability to retain this learning in working memory in order to establish a course of action. Alternatively, the lesion may have altered the relative contribution of action-outcome and outcome-action associations to instrumental performance. On this account, prelimbic lesions affect action-outcome encoding but leave outcome-action associations intact providing the basis for outcome-mediated initiation of an action sufficient, perhaps, to support acquisition and performance in the lesioned rats.

Obsessive-compulsive disorder in Bali: the cultural shaping of a neuropsychiatric disorder

Many psychiatric researchers believe that the clinical picture of obsessive-compulsive disorder (OCD) shows little variability cross-culturally. This study examined the symptomatology and illness experience of 19 patients suffering from OCD in Bali, Indonesia. Patients were assessed using a semi-structured clinical interview. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) was utilized for gauging symptomatology and severity of symptoms. A sub-sample of patients was interviewed using person-centered ethnographic techniques. Balinese culture strongly shaped symptomatic expression. The most common obsessional themes emphasized patients' obsessional need to know information about their social network, such as the identity and status of passers-by. Somatic obsessions and religious themes around witchcraft and spirits were also prominent. Psychiatric, indigenous and anthropological perspectives are contrasted to highlight the power and limitations of each to explain OCD.

Evolutionary psychiatry. Adaptationist and nonadaptationist conceptualizations

Darwin's theory of evolution, and in particular one of its mechanisms, natural selection, is being used as the explanatory cornerstone of many unsolved problems in human biology and human affairs. Psychiatry is an example of that. Darwinian psychiatry's main proponents endorse the adaptationist program to carry out their project to implement an evolutionary psychiatry. The adaptationist program is an attempt to view all evolutionary novelties as adaptations, i.e., classically, features that favour survival and/or reproduction. This position is definitely teleological, and anthropomorphism plays a central role in its construction. This paper takes issue with the adaptationist approach. We argue that organism-environment interactions are bidirectional processes. Hence, as a result of the fact that "a surprisingly large amount of the environment, which affects natural selection on an animal is the more or less direct result of the animals own behavior" [Waddington, C.H., 1976. Evolution of the subhuman world. In: Jantsch, E., Waddington, C.H. (Eds.), Evolution of Consciousness. London, UK, pp. 11-23], a more appropriate term to describe these interactions appears to be construction rather than adaptation alone [Lewontin, R., 2000. The triple helix: gene organism and environment. Harvard Univ. Press]. We present factual anatomical, physiological and clinical data critical of the platonic Kraepelinean classification of mental diseases, and claim that this classification is contrary to modern ideas on the evolution of nervous systems. We argue against the view of mainstream evolutionary psychiatrists that mental diseases are adaptations. We do so on two accounts. One is methodological; authors in this position do not ask whether every disease has evolutionary causes, but assume this in order to explain all diseases in such terms. The other mistake is biological; it is their belief that adaptation is the driving force of evolution while in fact it is just an outcome of evolution. The current status of the controversy between cognitive versus emotional experiences as essentially independent is reviewed, and evidence is presented, that they cannot be considered platonic, categorically independent functions of CNSs. These data, taken together, plus arguments derived from the high degree of plasticity of nervous systems, lead us to suggest a different approach to classification of mental diseases.

Neuropsychology of fear and loathing

For over 60 years, ideas about emotion in neuroscience and psychology have been dominated by a debate on whether emotion can be encompassed within a single, unifying model. In neuroscience, this approach is epitomized by the limbic system theory and, in psychology, by dimensional models of emotion. Comparative research has gradually eroded the limbic model, and some scientists have proposed that certain individual emotions are represented separately in the brain. Evidence from humans consistent with this approach has recently been obtained by studies indicating that signals of fear and disgust are processed by distinct neural substrates. We review this research and its implications for theories of emotion.

Connections underlying the synthesis of cognition, memory, and emotion in primate prefrontal cortices

Distinct domains of the prefrontal cortex in primates have a set of connections suggesting that they have different roles in cognition, memory, and emotion. Caudal lateral prefrontal areas (areas 8 and 46) receive projections from cortices representing early stages in visual or auditory processing, and from intraparietal and posterior cingulate areas associated with oculomotor guidance and attentional processes. Cortical input to areas 46 and 8 is complemented by projections from the thalamic multiform and parvicellular sectors of the mediodorsal nucleus associated with oculomotor functions and working memory. In contrast, caudal orbitofrontal areas receive diverse input from cortices representing late stages of processing within every unimodal sensory cortical system. In addition, orbitofrontal and caudal medial (limbic) prefrontal cortices receive robust projections from the amygdala, associated with emotional memory, and from medial temporal and thalamic structures associated with long-term memory. Prefrontal cortices are linked with motor control structures related to their specific roles in central executive functions. Caudal lateral prefrontal areas project to brainstem oculomotor structures, and are connected with premotor cortices effecting head, limb and body movements. In contrast, medial prefrontal and orbitofrontal limbic cortices project to hypothalamic visceromotor centers for the expression of emotions. Lateral, orbitofrontal, and medial prefrontal cortices are robustly interconnected, suggesting that they participate in concert in central executive functions. Prefrontal limbic cortices issue widespread projections through their deep layers and terminate in the upper layers of lateral (eulaminate) cortices, suggesting a predominant role in feedback communication. In contrast, when lateral prefrontal cortices communicate with limbic areas they issue projections from their upper layers and their axons terminate in the deep layers, suggesting a role in feedforward communication. Through their widespread connections, prefrontal limbic cortices may exercise a tonic influence on lateral prefrontal cortices, inextricably linking areas associated with cognitive and emotional processes. The integration of cognitive, mnemonic and emotional processes is likely to be disrupted in psychiatric and neurodegenerative diseases which preferentially affect limbic cortices and consequently disconnect major feedback pathways to the neuraxis.