When too much is not enough: obsessive-compulsive disorder as a pathology of stopping, rather than starting

Dynamics of self-control during choice and post-choice consumption quantity

Observed choices between options representing a relative vice and a relative virtue have commonly been used as a measure of eating self-control in the literature. However, even though self-control operations may manifest across the post-choice consumption stage, either similarly or in different ways from the choice stage, most prior research has ignored consumption quantity of the chosen option. While the behavior of choosing a virtue instead of a vice does manifest self-control, we examine how this plays out in post-choice consumption. Specifically, we find that when processing resources are limited, after having chosen a virtue food, unrestrained eaters ironically consumed greater quantities and therefore more calories than restrained eaters (Study 1). This reflects more persistent self-control in the post-choice consumption stage among restrained eaters than unrestrained eaters, and occurs because choosing a virtue lowers accessibility of the self-control goal among unrestrained eaters relative to restrained eaters (Study 2), thereby increasing intake of the virtuous food. In contrast, subsequent to having chosen a vice, unrestrained eaters and restrained eaters did not show any such difference in intake (Study 1) or goal accessibility (Study 2). Together, these results reveal that persistence of self-control in the post-choice consumption stage depends on individuals' dietary restraint and their initial exercise of self-control in the choice decision. The mere act of choosing a virtue satisfies unrestrained eaters' self-control goal and leads to increased food intake, whereas the same act keeps the same goal activated among restrained eaters who reduce intake of the chosen virtue. Put differently, persistent self-control across choice and quantity decisions is observed only when those with a dietary goal show successful self-control enactment in the choice stage. We therefore highlight that the operation of self-control can be dynamic within a consumption episode, and thus, choice and post-choice quantity are both informative of self-control.

Too much of a good thing? Hand hygiene and the long-term course of contamination-related obsessive-compulsive symptoms

Increased hygiene behavior may be a factor in the development of contamination-related obsessive-compulsive symptoms (C-OCS). We aimed at investigating (1) the course of C-OCS over 1 year after the start of the COVID-19 pandemic and (2) the effects of changes in hand hygiene (i.e., duration and frequency of handwashing) and related distress regulation on the long-term course of C-OCS. In a longitudinal study, we assessed 1,220 individuals from the German general population at the start of the COVID-19 pandemic (t1), 3 months later (t2), and 12 months later (t3). Pre-pandemic data were available in a subsample from 2014 (n = 430). A decrease in C-OCS over the first year of the pandemic emerged with a small effect size. Thirty-six percent of the participants scored above the clinical cut-off score at t1, 31% at t2, and 27% at t3. In 2014, only 11% scored above the clinical cut-off score. Hierarchical regression showed that C-OCS at t1 was the strongest predictor of a long-term increase in C-OCS. With small effect sizes, change in the duration (not frequency) of handwashing from t1 to t2, as well as the distress-reducing effect of handwashing served as additional predictors. Implications for information on hand hygiene guidelines are discussed.

Dr. Jack Rachman's contributions to our understanding and treatment of obsessive-compulsive disorder

BACKGROUND AND OBJECTIVES

This paper reviews the development of the cognitive-behavioural model of obsessive-compulsive disorder (OCD) through the work of Dr. Jack Rachman and the research his ideas inspired or shaped.

METHODS

A narrative review of Rachman's work and important developments in related areas was conducted.

RESULTS

Rachman was highly responsive to theoretical and empirical developments in the field, and continuously developed his model of OCD over the course of his career. Key developments in his thinking and of those in related areas are described.

LIMITATIONS

This is a narrative review that highlights important developments in the cognitive behavioural model of OCD only.

CONCLUSIONS

The CBT model of OCD has strong empirical support and CBT treatment is the most effective psychotherapy. Continued development in our understanding of attachment and in the persistence of compulsions is warranted.

Escitalopram and lorazepam differentially affect nesting and open field behaviour in deer mice exposed to an anxiogenic environment

Large nest building behaviour (LNB), as expressed by a subpopulation of laboratory housed deer mice (Peromyscus maniculatus bairdii), is persistent and repetitive. However, the response of LNB to an anxiogenic environment has not yet been investigated. Here, we employed LNB and normal nesting (NNB) expressing mice, subdivided into three drug-exposed groups per cohort, i.e. water (28 days), escitalopram (50 mg/kg/day, 28 days) and lorazepam (2 mg/kg/day; 4 days) to investigate this theme. During the last 4 days of drug exposure, mice were placed inside anxiogenic open field arenas which contained a separate enclosed and dark area for 4 consecutive nights during which open field and/or nest building assessments were performed. We show that LNB behaviour in deer mice is stable, irrespective of the anxiety-related context in which it is assessed, and that LNB mice find an open field arena to be less aversive compared to NNB mice. Escitalopram and lorazepam differentially affected the nesting and open field behaviour of LNB expressing mice, confirming deer mouse LNB as a repetitive behavioural phenotype that is related to a compulsive-like process which is regulated by the serotonergic system.

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.

A study of the Repeated Actions Diary in patients suffering from obsessive compulsive disorder

The structured Repeated Action Diary (RAD) collects in vivo data on compulsions and their various characteristics. Certain compulsions (i.e., those ending because the patient feels certain that it is safe to stop) are then compared with uncertain compulsions. The compulsion profile in patients with obsessive compulsive disorder (OCD) was assessed by using the RAD. Thirty-two patients from two sources participated in the study. Before pooling the two subgroups, we checked that they did not differ significantly with regard to demographic and clinical variables. Patients reported several categories of compulsion. The most frequently reported compulsions were washing and checking. In a given person, checking compulsions (in contrast to washing compulsions) were often produced by several different obsessions. Almost all the patients reported repeating the compulsions because of a need to feel sure. There were far more "certain" compulsions than "uncertain" compulsions. The number of repetitions was significantly lower for certain compulsions than for uncertain compulsions. The person felt greater relief from guilt and responsibility and a greater decrease in discomfort at the end of a compulsive episode for certain compulsions than for uncertain compulsions. In conclusion, the need to ritualize (prompted by uncertainty, i.e., potential danger) might explain the maintenance (or posttreatment recurrence) of OCD in many patients. The need for certainty in the completion of a compulsion may be worth considering as a therapeutic tool. The development of an approach based on the need for certainty might help to improve treatment outcomes.

Dopaminergic and serotonergic modulation of social reward appraisal in zebrafish (Danio rerio) under circumstances of motivational conflict: Towards a screening test for anti-compulsive drug action

Cognitive flexibility, shown to be impaired in patients presenting with compulsions, is dependent on balanced dopaminergic and serotonergic interaction. Towards the development of a zebrafish (Danio rerio) screening test for anti-compulsive drug action, we manipulated social reward appraisal under different contexts by means of dopaminergic (apomorphine) and serotonergic (escitalopram) intervention. Seven groups of zebrafish (n = 6 per group) were exposed for 24 days (1 h per day) to either control (normal tank water), apomorphine (50 or 100 μg/L), escitalopram (500 or 1000 μg/L) or a combination (A100/E500 or A100/E1000 μg/L). Contextual reward appraisal was assessed over three phases i.e. Phase 1 (contingency association), Phase 2 (dissociative testing), and Phase 3 (re-associative testing). We demonstrate that 1) sight of social conspecifics is an inadequate motivational reinforcer under circumstances of motivational conflict, 2) dopaminergic and serotonergic intervention lessens the importance of an aversive stimulus, increasing the motivational valence of social reward, 3) while serotoninergic intervention maintains reward directed behavior, high-dose dopaminergic intervention bolsters cue-directed responses and 4) high-dose escitalopram reversed apomorphine-induced behavioral inflexibility. The results reported here are supportive of current dopamine-serotonin opponency theories and confirm the zebrafish as a potentially useful species in which to investigate compulsive-like behaviors.

Dissociable dopaminergic and pavlovian influences in goal-trackers and sign-trackers on a model of compulsive checking in OCD

RATIONALE

Checking is a functional behaviour that provides information to guide behaviour. However, in obsessive-compulsive disorder (OCD), checking may escalate to dysfunctional levels. The processes underpinning the transition from functional to dysfunctional checking are unclear but may be associated with individual differences that support the development of maladaptive behaviour. We examined one such predisposition, sign-tracking to a pavlovian conditioned stimulus, which we previously found associated with dysfunctional checking. How sign-tracking interacts with another treatment with emerging translational validity for OCD-like checking, chronic administration of the dopamine D₂ receptor agonist quinpirole, is unknown.

OBJECTIVES

We tested how functional and dysfunctional checking in the rat observing response task (ORT) was affected by chronic quinpirole administration in non-autoshaped controls and autoshaped animals classified as sign-trackers or goal-trackers.

METHODS

Sign-trackers or goal-trackers were trained on the ORT before the effects of chronic quinpirole administration on checking were assessed. Subsequently, the effects on checking of different behavioural challenges, including reward omission and the use of unpredictable reinforcement schedules, were tested.

RESULTS

Prior autoshaping increased checking. Sign-trackers and goal-trackers responded differently to quinpirole sensitization, reward omission and reinforcement uncertainty. Sign-trackers showed greater elevations in dysfunctional checking, particularly during uncertainty. By contrast, goal-trackers predominantly increased functional checking responses, possibly in response to reduced discrimination accuracy in the absence of cues signalling which lever was currently active.

CONCLUSIONS

The results are discussed in terms of how pavlovian associations influence behaviour that becomes compulsive in OCD and how this may be dependent on striatal dopamine D₂ receptors.

Contributions of the basal ganglia to action sequence learning and performance

Animals engage in intricately woven and choreographed action sequences that are constructed from trial-and-error learning. The mechanisms by which the brain links together individual actions which are later recalled as fluid chains of behavior are not fully understood, but there is broad consensus that the basal ganglia play a crucial role in this process. This paper presents a comprehensive review of the role of the basal ganglia in action sequencing, with a focus on whether the computational framework of reinforcement learning can capture key behavioral features of sequencing and the neural mechanisms that underlie them. While a simple neurocomputational model of reinforcement learning can capture key features of action sequence learning, this model is not sufficient to capture goal-directed control of sequences or their hierarchical representation. The hierarchical structure of action sequences, in particular, poses a challenge for building better models of action sequencing, and it is in this regard that further investigations into basal ganglia information processing may be informative.

Obsessive compulsive disorder (OCD): Current treatments and a framework for neurotherapeutic research

We briefly review current approaches to the diagnosis and treatment of OCD, noting their lack of a strong theoretical foundation. In keeping with the Research Domain Criteria project (RDoC) calls for reconceptualizing psychopathology in ways that better link up with normal brain systems, we advance an adaptationist, brain-network perspective on OCD and propose that OCD represents a dysfunction in the stopping dynamics of a normal brain network that evolved to handle potential danger. We then illustrate how this theoretical perspective can be used to organize possibilities for research on neurotherapeutics for OCD and suggest novel directions for future work.

Visibility and transmission: complexities around promoting hand hygiene in young children - a qualitative study

Background

Effective hand hygiene practice can reduce transmission of diseases such as respiratory tract infections (RTIs) and gastrointestinal infections, especially in young children. While hand hygiene has been widely promoted within Australia, primary care providers’ (PCPs) and parents’ understanding of hand hygiene importance, and their views on hand hygiene in reducing transmission of diseases in the community are unclear. Therefore, the aim of this study was to explore the views of PCPs and parents of young children on their knowledge and practice of hand hygiene in disease transmission.

Methods

Using a cross-sectional qualitative research design, we conducted 30 in-depth interviews with PCPs and five focus groups with parents (n = 50) between June 2014 and July 2015 in Melbourne, Australia. Data were thematically analysed.

Results

Participants agreed that hand hygiene practice was important in reducing disease transmissions. However, barriers such as variations of hand hygiene habits, relating visibility to transmission; concerns around young children being obsessed with washing hands; children already being ‘too clean’ and the need to build their immunity through exposure to dirt; and scepticism that hand hygiene practice was achievable in young children, all hindered participants’ motivation to develop good hand hygiene behaviour in young children.

Conclusion

Despite the established benefits of hand hygiene, sustained efforts are needed to ensure its uptake in routine care. To overcome the barriers identified in this study a multifaceted intervention is needed that includes teaching young children good hand hygiene habits, PCPs prompting parents and young children to practice hand hygiene when coming for an RTI consultation, reassuring parents that effective hand hygiene practice will not lead to abnormal psychological behaviour in their children, and community health promotion education campaigns.

Value-based decision making under uncertainty in hoarding and obsessive- compulsive disorders

Difficulties in decision making are a core impairment in a range of disease states. For instance, both obsessive- compulsive disorder (OCD) and hoarding disorder (HD) are associated with indecisiveness, inefficient planning, and enhanced uncertainty intolerance, even in contexts unrelated to their core symptomology. We examined decision-making patterns in 19 individuals with OCD, 19 individuals with HD, 19 individuals with comorbid OCD and HD, and 57 individuals from the general population, using a well-validated choice task grounded in behavioral economic theory. Our results suggest that difficulties in decision making in individuals with OCD (with or without comorbid HD) are linked to reduced fidelity of value-based decision making (i.e. increase in inconsistent choices). In contrast, we find that performance of individuals with HD on our laboratory task is largely intact. Overall, these results support our hypothesis that decision-making impairments in OCD and HD, which can appear quite similar clinically, have importantly different underpinnings. Systematic investigation of different aspects of decision making, under varying conditions, may shed new light on commonalities between and distinctions among clinical syndromes.

Obsessive-compulsive disorder: Insights from animal models

Research with animal models of obsessive-compulsive disorder (OCD) shows the following: (1) Optogenetic studies in mice provide evidence for a plausible cause-effect relation between increased activity in cortico-basal ganglia-thalamo-cortical (CBGTC) circuits and OCD by demonstrating the induction of compulsive behavior with the experimental manipulation of the CBGTC circuit. (2) Parallel use of several animal models is a fruitful paradigm to examine the mechanisms of treatment effects of deep brain stimulation in distinct OCD endophenotypes. (3) Features of spontaneous behavior in deer mice constitute a rich platform to investigate the neurobiology of OCD, social ramifications of a compulsive phenotype, and test novel drugs. (4) Studies in animal models for psychiatric disorders comorbid with OCD suggest comorbidity may involve shared neural circuits controlling expression of compulsive behavior. (5) Analysis of compulsive behavior into its constitutive components provides evidence from an animal model for a motivational perspective on OCD. (6) Methods of behavioral analysis in an animal model translate to dissection of compulsive rituals in OCD patients, leading to diagnostic tests.

Unintended Consequences of Security Motivation in the Age of the Internet: Impacts on Governance and Democracy

There has been a striking recent shift in how political discourse seems to work, with, for example, partial information of sometimes dubious accuracy or relevance propagating very rapidly and widely on electronic networks and overriding clearer, more complete, more accurate information. In explanation of such phenomena, we address ways in which highly interconnected electronic networks may create vulnerabilities that involve tapping into special, relatively hard-wired motivational systems in the brain, particularly the security motivation system. We also discuss a mode of communication, sometimes described as “mass hypnosis,” in relation to a motivational system that manages the dominance hierarchy. Rather than just affecting people’s higher cognitions, political messages also tap into these motivation systems, generating surprising avenues for misuse.

Effects of context on risk taking and decision times in obsessive-compulsive disorder

Despite the fact that OCD patients show altered decision making in everyday life, few studies have investigated how patients make risky decisions and what contextual factors impact choices. We investigated cognitive context with the use of the "framing effect" task, which investigates decision making based on whether monetarily equivalent choice options are framed in terms of a potential to either lose (lose $20 out of $50) or gain (gain $30 out of $50) money. In addition, we manipulated social context by providing positive or neutral feedback on subjects' choices. Overall, participants were risk taking for options framed in terms of potential loss and risk averse for options framed in terms of potential gain (the classic framing effect). Although OCD patients were generally more risk averse, the effect of the frame on choices did not differ significantly from healthy participants and choices were not impacted by social context. Within OCD patients, greater self-reported indecisiveness was associated with a larger effect of the frame on choices. OCD patients were also significantly slower to make choices in the loss compared to gain frame, an effect that was not observed among healthy participants. Overall, our results suggest that the framing of choice options has a differential effect on decision times but not the actual choices made by OCD patients, and that patients are not sensitive to social feedback when making choices. The correlation between indecisiveness and the framing effect in OCD suggests that further work interrogating the relationship between specific symptoms and decision making among patients may yield new insights into the disorder.

Role of the dorsal anterior cingulate cortex in obsessive-compulsive disorder: converging evidence from cognitive neuroscience and psychiatric neurosurgery

OBJECTIVE Advances in understanding the neurobiological basis of psychiatric disorders will improve the ability to refine neuromodulatory procedures for treatment-refractory patients. One of the core dysfunctions in obsessive-compulsive disorder (OCD) is a deficit in cognitive control, especially involving the dorsal anterior cingulate cortex (dACC). The authors' aim was to derive a neurobiological understanding of the successful treatment of refractory OCD with psychiatric neurosurgical procedures targeting the dACC. METHODS First, the authors systematically conducted a review of the literature on the role of the dACC in OCD by using the search terms "obsessive compulsive disorder" and "anterior cingulate." The neuroscience literature on cognitive control mechanisms in the dACC was then combined with the literature on psychiatric neurosurgical procedures targeting the dACC for the treatment of refractory OCD. RESULTS The authors reviewed 89 studies covering topics that included structural and functional neuroimaging and electrophysiology. The majority of resting-state functional neuroimaging studies demonstrated dACC hyperactivity in patients with OCD relative to that in controls, while task-based studies were more variable. Electrophysiological studies showed altered dACC-related biomarkers of cognitive control, such as error-related negativity in OCD patients. These studies were combined with the cognitive control neurophysiology literature, including the recently elaborated expected value of control theory of dACC function. The authors suggest that a central feature of OCD pathophysiology involves the generation of mis-specified cognitive control signals by the dACC, and they elaborate on this theory and provide suggestions for further study. CONCLUSIONS Although abnormalities in brain structure and function in OCD are distributed across a wide network, the dACC plays a central role. The authors propose a theory of cognitive control dysfunction in OCD that attempts to explain the therapeutic efficacy of dACC neuromodulation. This theoretical framework should help to guide further research into targeted treatments of OCD and other disorders of cognitive control.

Learning From Animal Models of Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) affects 2%-3% of the population worldwide and can cause significant distress and disability. Substantial challenges remain in the field of OCD research and therapeutics. Approved interventions alleviate symptoms only partially, with 30%-40% of patients being resistant to treatment. Although the etiology of OCD is still unknown, research evidence points toward the involvement of cortico-striato-thalamocortical circuitry. This review focuses on the most recent behavioral, genetics, and neurophysiologic findings from animal models of OCD. Based on evidence from these models and parallels with human studies, we discuss the circuit hyperactivity hypothesis for OCD, a potential circuitry dysfunction of action termination, and the involvement of candidate genes. Adding a more biologically valid framework to OCD will help researchers define and test new hypotheses and facilitate the development of targeted therapies based on disease-specific mechanisms.

Can doubt attenuate access to internal states? Implications for obsessive-compulsive disorder

BACKGROUND AND OBJECTIVES

We have previously reported that obsessive-compulsive individuals perform more poorly on tasks that require accurate perception of internal states. As these individuals are also characterized by elevated levels of doubt regarding internal states, the causal relationship between doubt and accurate perception remained unclear. The presented study examines whether undermining participants' confidence in their ability to accurately produce a specific internal state would affect their performance on a task that requires accurate perception of this state.

METHODS

Participants were trained to produce specific levels of forearm muscle tension and then required to produce various tension levels in four experimental phases. The first three alternated in terms of whether the participants viewed a biofeedback monitor while the fourth offered participants several times the choice to view the monitor. Prior to the task, half of the participants received instructions that undermined their confidence in their ability to accurately assess their own muscle tension. We measured participants' accuracy in producing the required muscle tension levels and the number of times they requested to view the monitor in the final phase.

RESULTS

Undermined confidence participants were less accurate in producing the required muscle tension levels in the absence of biofeedback, and were also more likely to request the monitor in the final phase.

CONCLUSIONS

Doubt can affect performance on tasks that require perceiving and experiencing internal states. This finding supports the possibility that access to internal states in OCD is attenuated due to elevated levels of doubt regarding these states.

In the wake of a possible mistake: Security motivation, checking behavior, and OCD

BACKGROUND AND OBJECTIVES

In previous experiments, OCD washers did not differ significantly from controls in their initial level of activation in response to the potential threat of contamination; however, they were less able to reduce their activation by engaging in hand-washing, suggesting that the key problem in OCD is a faulty stopping mechanism. The main objectives of the present experiments were to develop a similar experimental paradigm for investigating checking behavior, and to use it to test the hypothesis that a faulty stopping mechanism also underlies OCD checking.

METHODS

Participants sorted pills under the guise of beta testing a new medication system and then were given suggestions of the possibility of having made mistakes with potentially serious consequences. Later, participants engaged in a 90-s checking period and an unlimited period of checking. At baseline and three other times during the experiment, security motivation was measured with respiratory sinus arrhythmia (RSA) and subjective ratings of confidence. Experiment 1 established the parameters of the paradigm in non-patient participants, and Experiment 2 contrasted OCD checkers with OCD washers and non-patients.

RESULTS

Results for both subjective and physiological measures of security motivation closely replicated previous findings for washing behavior. Groups did not differ significantly in initial activation, but the OCD checkers were unable to reduce their activation by engaging in period of checking that was ample for returning controls to baseline.

LIMITATIONS

The sample size for the patient groups was modest.

CONCLUSIONS

These results lend further support to the security-motivation theory of OCD.

From Thought to Action: How the Interplay Between Neuroscience and Phenomenology Changed Our Understanding of Obsessive-Compulsive Disorder

The understanding of obsessive-compulsive disorder (OCD) has evolved with the knowledge of behavior, the brain, and their relationship. Modern views of OCD as a neuropsychiatric disorder originated from early lesion studies, with more recent models incorporating detailed neuropsychological findings, such as perseveration in set-shifting tasks, and findings of altered brain structure and function, namely of orbitofrontal corticostriatal circuits and their limbic connections. Interestingly, as neurobiological models of OCD evolved from cortical and cognitive to sub-cortical and behavioral, the focus of OCD phenomenology also moved from thought control and contents to new concepts rooted in animal models of action control. Most recently, the proposed analogy between habitual action control and compulsive behavior has led to the hypothesis that individuals suffering from OCD may be predisposed to rely excessively on habitual rather than on goal-directed behavioral strategies. Alternatively, compulsions have been proposed to result either from hyper-valuation of certain actions and/or their outcomes, or from excessive uncertainty in the monitoring of action performance, both leading to perseveration in prepotent actions such as washing or checking. In short, the last decades have witnessed a formidable renovation in the pathophysiology, phenomenology, and even semantics, of OCD. Nevertheless, such progress is challenged by several caveats, not least psychopathological oversimplification and overgeneralization of animal to human extrapolations. Here we present an historical overview of the understanding of OCD, highlighting converging studies and trends in neuroscience, psychiatry and neuropsychology, and how they influenced current perspectives on the nosology and phenomenology of this disorder.

Frontal EEG alpha activity and obsessive-compulsive behaviors in non-clinical young adults: a pilot study

Previous studies have shown that the resting electroencephalogram (EEG) alpha patterns of non-clinical participants who score high on measures of negative affect, such as depression and shyness, are different from those who score low. However, we know relatively little about patterns of resting EEG alpha patterns in a non-clinical sample of individuals with high levels of obsessive-compulsive behaviors indicative of obsessive-compulsive disorder (OCD). Here we measured resting EEG alpha activity in frontal and parietal regions of non-clinical participants who scored high and low on the Padua-R, a measure of the severity of OCD-related behaviors. We found that participants who scored high on the Padua-R exhibited decreased overall activity in frontal regions relative to individuals who scored low on the measure. We speculate that frontal hypoactivity may be a possible marker and/or index of risk for OCD.

"Not Just Right Experiences" are specific to obsessive-compulsive disorder: further evidence from Italian clinical samples

Not Just Right Experiences (NJREs) are considered to be a perceptually tinged phenomenon mainly related to obsessive-compulsive disorder (OCD). The evidence of an association between NJREs and OCD or OC symptoms have been accumulating in the last few years, whereas there is a paucity of studies about the role of this construct in other clinical conditions considered part of the "OCD spectrum". In the current study, the NJRE-Q-R Severity scale (a well-validated measure of NJREs) was administered to 41 patients with OCD, 53 with hair-pulling disorder (HPD), 38 with gambling disorder (GD) and 43 with eating disorders (ED) along with measures of OC symptoms and general distress. In each group, NJREs were consistently associated with OC symptoms; moreover, the pattern of associations appeared coherent with the main clinical features of each disorder. The OCD group reported higher levels of NJREs severity than GD and ED, whereas there were no differences between the OCD and HPD groups. However, HPD patients did not have higher scores of NJREs severity than GD and ED counterparts. NJREs appear to be specific to OCD, but further study is needed to establish the role of this construct in OCD-related disorders.

Nucleus accumbens core and pathogenesis of compulsive checking

To investigate the role of the nucleus accumbens core (NAc) in the development of quinpirole-induced compulsive checking, rats received an excitotoxic lesion of NAc or sham lesion and were injected with quinpirole (0.5 mg/kg) or saline; development of checking behavior was monitored for 10 biweekly tests. The results showed that even after the NAc lesion, quinpirole still induced compulsive checking, suggesting that the pathogenic effects produced by quinpirole lie outside the NAc. Although the NAc lesion did not prevent the induction of compulsive checking, it altered how quickly it develops, suggesting that the NAc normally contributes toward the induction of compulsive checking. Saline-treated rats with an NAc lesion were hyperactive, but did not develop compulsive checking, indicating that hyperactivity by itself is not sufficient for the pathogenesis of compulsive checking. It is proposed that compulsive checking is the exaggerated output of a security motivation system and that the NAc serves as a neural hub for coordinating the orderly activity of neural modules of this motivational system. Evidence is considered suggesting that the neurobiological condition for the pathogenesis of compulsive checking is two-fold: activation of dopamine D2/D3 receptors without concurrent stimulation of D1-like receptors and long-term plastic changes related to quinpirole-induced sensitization.

Striatal circuits, habits, and implications for obsessive-compulsive disorder

Increasing evidence implicates abnormalities in corticostriatal circuits in the pathophysiology of obsessive-compulsive disorder (OCD) and OC-spectrum disorders. Parallels between the emergence of repetitive, compulsive behaviors and the acquisition of automated behaviors suggest that the expression of compulsions could in part involve loss of control of such habitual behaviors. The view that striatal circuit dysfunction is involved in OC-spectrum disorders is strengthened by imaging and other evidence in humans, by discovery of genes related to OCD syndromes, and by functional studies in animal models of these disorders. We highlight this growing concordance of work in genetics and neurobiology suggesting that frontostriatal circuits, and their links with basal ganglia, thalamus and brainstem, are promising candidates for therapeutic intervention in OCD.

Separate mechanisms for development and performance of compulsive checking in the quinpirole sensitization rat model of obsessive-compulsive disorder (OCD)

RATIONALE

Acute administration of serotonergic agonist, meta-chlorophenylpiperazine (mCPP), attenuates performance of compulsive checking in an animal model of obsessive-compulsive disorder (OCD). It is not known whether mCPP has a similar effect on development of compulsive checking.

OBJECTIVES

The objective of the study was to examine whether similar mechanisms mediate the development versus the performance of compulsive checking in the rat model.

METHODS

Four groups of male rats (N = 14/group) were tested: two experimental groups co-injected with D2/D3 dopamine agonist quinpirole (0.25 mg/kg) and mCPP (0.625 mg/kg or 1.25 mg/kg), and two control groups, one co-injected with quinpirole and saline, the other receiving injections of saline. The time course of development of compulsive checking across injections 1 to 10 in quinpirole-treated rats was compared to rats co-injected with quinpirole and mCPP.

RESULTS

Results showed that during the course of chronic treatment, mCPP (1.25 mg/kg) significantly attenuated performance of checking behavior. However, when these rats were retested for expression of compulsive checking (that is, with an injection of quinpirole only), their profile of compulsive checking was no different from the control rats treated throughout with quinpirole only.

CONCLUSIONS

Findings show that mCPP inhibits performance of compulsive checking but does not block quinpirole from inducing the neural substrate underlying this compulsive behavior. Hence, a separate mechanism underlies the induction of compulsive checking and the performance of it. It is suggested that development of the OCD endophenotype reflects neuroplastic changes produced by repeated dopamine D2/D3 receptor stimulation, while stimulation of serotonergic receptors mediates a negative feedback signal that shuts down the motor performance of checking.

Differential role of visuospatial working memory in the propensity toward uncertainty in patients with obsessive-compulsive disorder and in healthy subjects

BACKGROUND

Obsessive-compulsive disorder (OCD) is associated with visuospatial working memory deficits. Intolerance of uncertainty is thought to be a core component of OCD symptoms. Recent findings argue for a possible relationship between abilities in visuospatial memory and uncertainty. However, this relationship remains unclear in both OCD patients and healthy subjects. To address this issue, we measured performance in visuospatial working memory and the propensity to express uncertainty during decision making. We assessed their relationship and the temporal direction of this relationship in both OCD patients and healthy subjects.

METHOD

Baseline abilities in visuospatial working memory were measured with the Corsi block-tapping test. A delayed matching-to-sample task was used to identify explicit situations of certainty, uncertainty and ignorance and to assess continuous performance in visuospatial working memory. Behavioural variables were recorded over 360 consecutive trials in both groups.

RESULTS

Baseline scores of visuospatial working memory did not predict the number of uncertain situations in OCD patients whereas they did in healthy subjects. Uncertain trials led to reduced abilities in visuospatial working memory to 65% of usual performance in OCD patients whereas they remained stable in healthy subjects.

CONCLUSIONS

The present findings show an opposite temporal direction in the relationship between abilities in working memory and uncertainty in OCD patients and healthy subjects. Poor working memory performance contributes to the propensity to feel uncertainty in healthy subjects whereas uncertainty contributes to decreased continuous performance in working memory in OCD patients.

Performance of compulsive behavior in rats is not a unitary phenomenon - validation of separate functional components in compulsive checking behavior

A previous analysis of the quinpirole sensitisation rat model of obsessive-compulsive disorder revealed that the behavioral phenotype of compulsive checking consists of three constitutive components – vigor of checking performance, focus on the task of checking, and satiety following a bout of checking. As confirmation of this analysis, the aim of the present study was to reconstitute, without quinpirole treatment, each of the putative components, with the expectation that these would self-assemble into compulsive checking. To reconstitute vigor and satiety, the employed treatment was a bilateral lesion of the nucleus accumbens core (NAc), as this treatment was shown previously to exaggerate these components. To reconstitute focus, the employed treatment was a low dose of the serotonin-1A receptor agonist 8-hydroxy-2-(di-n-propylamino) tetralin hydrochloride (DPAT) (0.0625 mg/kg), as high doses of this drug induce compulsive behavior and exacerbate focus. Results showed that injection of DPAT to NAc lesion rats did yield compulsive checking. Neither the drug alone nor the NAc lesion by itself produced compulsive checking. The demonstrated synthesis of compulsive checking by the combined treatment of low-dose DPAT and NAc lesion strengthened the previous fractionation of the model obsessive-compulsive disorder phenotype into three constitutive components, and suggested a role for serotonin-1A receptors outside the NAc in enhanced focus on the task of checking.

Dimensions of Perfectionism in Children and Adolescents with Obsessive-compulsive Disorder

OBJECTIVE

To measure the association of perfectionism with obsessive-compulsive and depressive symptoms in children and adolescents with obsessive-compulsive disorder (OCD).

METHOD

Sample consisted of 94 youth (44 boys, 49 girls; mean age = 13.2 y, SD = 2.5 y) with a DSM-IV diagnosis of OCD. Perfectionism beliefs were measured with both the Adaptive/Maladaptive Perfectionism Scale (AMPS) and a 14-item version of the Child and Adolescents Perfectionism Scale (CAPS-14). Using a hierarchical linear-regression model, we measured the association of perfectionist beliefs with severity of OCD and depressive symptoms.

RESULTS

Both AMPS and CAPS-14 scores were associated with the severity of OCD symptoms in our sample. In addition, CAPS-14 scores were associated with the severity of depressive symptoms, even when OCD symptoms were taken into account.

CONCLUSIONS

Our findings lend further support to the hypothesis that perfectionism in youth with OCD is associated with variation in the severity of OCD and depressive symptoms.

The dopamine D2/D3 receptor agonist quinpirole increases checking-like behaviour in an operant observing response task with uncertain reinforcement: a novel possible model of OCD

Excessive checking is a common, debilitating symptom of obsessive-compulsive disorder (OCD). In an established rodent model of OCD checking behaviour, quinpirole (dopamine D2/3-receptor agonist) increased checking in open-field tests, indicating dopaminergic modulation of checking-like behaviours. We designed a novel operant paradigm for rats (observing response task (ORT)) to further examine cognitive processes underpinning checking behaviour and clarify how and why checking develops. We investigated i) how quinpirole increases checking, ii) dependence of these effects on D2/3 receptor function (following treatment with D2/3 receptor antagonist sulpiride) and iii) effects of reward uncertainty. In the ORT, rats pressed an 'observing' lever for information about the location of an 'active' lever that provided food reinforcement. High- and low-checkers (defined from baseline observing) received quinpirole (0.5mg/kg, 10 treatments) or vehicle. Parametric task manipulations assessed observing/checking under increasing task demands relating to reinforcement uncertainty (variable response requirement and active-lever location switching). Treatment with sulpiride further probed the pharmacological basis of long-term behavioural changes. Quinpirole selectively increased checking, both functional observing lever presses (OLPs) and non-functional extra OLPs (EOLPs). The increase in OLPs and EOLPs was long-lasting, without further quinpirole administration. Quinpirole did not affect the immediate ability to use information from checking. Vehicle and quinpirole-treated rats (VEH and QNP respectively) were selectively sensitive to different forms of uncertainty. Sulpiride reduced non-functional EOLPs in QNP rats but had no effect on functional OLPs. These data have implications for treatment of compulsive checking in OCD, particularly for serotonin-reuptake-inhibitor treatment-refractory cases, where supplementation with dopamine receptor antagonists may be beneficial.

A biological security motivation system for potential threats: are there implications for policy-making?

Research indicates that there is a specially adapted, hard-wired brain circuit, the security motivation system, which evolved to manage potential threats, such as the possibility of contamination or predation. The existence of this system may have important implications for policy-making related to security. The system is sensitive to partial, uncertain cues of potential danger, detection of which activates a persistent, potent motivational state of wariness or anxiety. This state motivates behaviors to probe the potential danger, such as checking, and to correct for it, such as washing. Engagement in these behaviors serves as the terminating feedback for the activation of the system. Because security motivation theory makes predictions about what kinds of stimuli activate security motivation and what conditions terminate it, the theory may have applications both in understanding how policy-makers can best influence others, such as the public, and also in understanding the behavior of policy-makers themselves.

Contextual and behavioral influences on uncertainty in obsessive-compulsive disorder

INTRODUCTION

Behavioral adaptation generally follows the contextual changes arising from the consequences (rewards and punishments) of an action. According to the reciprocal determinism model, there is a mutual influence between external context, cognitive processes and behavior. The maladaptive behaviors observed in obsessive-compulsive disorder (OCD) have been hypothesized to result from the disruption of the interactions between these three entities. For this, we assessed the influence of error signals and checking behavior on prefrontal cortical functions during decision-making in 14 OCD patients and 14 matched healthy participants.

METHODS

We used a behavioral task designed to elicit intolerance of uncertainty (IU) followed by the free expression of checking behaviors, which was coupled with functional magnetic resonance imaging.

RESULTS

At the behavioral level, IU intensity was correlated to the number of checking behaviors in both checking OCD patients and healthy controls during decision-making. However, external error signals did not influence checking behaviors in OCD patients, whereas they appeared to trigger checking behaviors in healthy subjects. At the neural level, IU intensity was positively correlated with activation in the orbitofrontal cortex (OFC) in both the OCD and control groups. At the region of interest (ROI) level, error signals increased IU-related OFC activations; in contrast, checking behaviors contributed to decreasing these neural activations in the healthy subjects, but no such modulation was observed in the OCD patients.

CONCLUSIONS

Our results show that IU-related OFC dysfunctions are not under the influence of the context and the behavioral response in OCD, suggesting that alterations of the dynamic features for this neural network may contribute to the expression of OCD symptoms.