Turning order into chaos through repetition and addition of elementary acts in obsessive-compulsive disorder (OCD)

An investigation of the experience of control through the sense of agency in people with obsessive-compulsive disorder: a review and meta-analysis

The construct of sense of agency (SoA) has proven useful for understanding mechanisms underlying obsessive-compulsive disorder (OCD) phenomenology, especially in explaining the apparent dissociation in OCD between actual and perceived control over one's actions. Paradoxically, people with OCD appear to experience both diminished SoA (feeling unable to control their actions) and inflated SoA (having "magical" control over events). The present review investigated the extent to which the SoA is distorted in OCD, in terms of both implicit (ie, inferred from correlates and outcomes of voluntary actions) and explicit (ie, subjective judgment of one's control over an outcome) measures of SoA. Our search resulted in 15 studies that met the criteria for inclusion in a meta-analysis, where we also examined the potential moderating effects of the type of measure (explicit versus implicit) and of the actual control participants had over the outcome. We found that participants with OCD or with high levels of OCD symptoms show lower implicit measures of SoA and at the same time tend to overestimate their control in situations where they do not actually have it. Together, these findings support the hypothesized dissociation in OCD between actual and perceived control over one's actions.

On the automatic detection of enacted compulsive hand washing using commercially available wearable devices

BACKGROUND

Compulsive hand washing is one of the most frequent compulsions and includes highly ritualized, repetitive hand motions. Developing an algorithm that can automatically detect compulsive washing with off-the-shelf wearable devices is a first step toward developing more sophisticated sensor-based assessments and micro-interventions that might ultimately supplement cognitive behavioral therapy for obsessive-compulsive disorder (OCD).

OBJECTIVE

The main objective was to establish whether enacted compulsive hand washing can be distinguished from routine hand washing. This distinction will inform future research on the development of an algorithm that can automatically detect compulsive hand washing.

METHOD

Twenty-one participants were trained individually to wash their hands according to 1 of 5 scripted hand-washing procedures that were based on descriptions of pathological compulsive washes and additionally to wash their hands as they usually would, while wearing a smartwatch. Washes were video recorded to obtain validation data. To generate a baseline model, we opted to extract well-known features only (mean and variance of each sensor axis). We tested four classification models: linear support vector machine (SVM), SVM with radial basis functions, random forest (RF), and naive Bayes (NB). Leave-one-subject-out cross-validation was applied to gather F1, specificity, and sensitivity scores.

RESULTS

The best-performing parameters were a classification window duration of 10 s, with a mean-variance feature set calculated from quaternions, rate of turn, and magnetic flux measurements. The detection performance varied with the particular enacted compulsive hand wash (F1 range: 0.65-0.87). Overall, enacted compulsive and routine hand washing could be distinguished with an F1 score of 79% (user independent), a sensitivity of 84%, and a specificity of 30%.

CONCLUSIONS

Our analysis of the sensor data demonstrates that enacted compulsive hand washing could be distinguished from routine hand washing with acceptable sensitivity. However, specificity was low. This study is a starting point for a series of follow-ups, including the application in individuals diagnosed with OCD.

The motor profile of obsessive-compulsive rituals: psychopathological and evolutionary implications

BACKGROUND

Studies investigating obsessive-compulsive disorder from an ethological approach have highlighted a specific motor pattern of compulsive rituals with respect to corresponding ordinary behaviors. Particularly, compulsive motor profile is built through the repetition of acts, with prevalence of nonfunctional ones and redirection of attention to its basic structural units. These formal features would characterize ritual behavior throughout evolution, from nonhuman animals to human cultures. However, no study to date has investigated a possible relationship between such motor profile and underlying psychopathology. Therefore, the first objective of the study was to confirm previous findings on a larger sample size of obsessive patients; the second objective was to elucidate whether motor profile might be associated with obsessive-compulsive psychopathology and/or prepsychotic symptoms of schizophrenia.

METHODS

Twenty-one obsessive-compulsive outpatients provided a videotape of their rituals. An equal number of healthy controls, matched for sex and age, were registered for corresponding ordinary acts. Obsessive patients were administered the Yale-Brown Obsessive-Compulsive Scale, the Brown Assessment of Beliefs Scale, the Hamilton Rating Scale for Depression, and the Frankfurt Complaint Questionnaire.

RESULTS

The results of the present study confirm that ritual compulsions present a specific motor structure characterized by repetition of both functional and nonfunctional acts and their longer duration. Such a motor pattern is independent from obsessive-compulsive psychopathology, whereas it results specifically associated with prepsychotic symptoms of schizophrenia.

CONCLUSIONS

We argue that this association may reflect the adaptive significance of ritual behavior across evolution, that is, its homeostatic function in conditions of unpredictability.

Excessive checking for non-anxiogenic stimuli in obsessive-compulsive disorder

Background

Repetitive checking in obsessive-compulsive disorder (OCD) would serve to relieve obsession-related anxiety and/or to compensate memory deficit, but experimental literature on this subject is inconsistent. The main objective is to test the influence of obsession-related anxiety and memory on repetitive checking in OCD.

Methods

Twenty-three OCD checkers, 17 OCD non-checkers and 41 controls performed a delayed-matching-to-sample task with an unrestricted checking option. Some stimuli were obsession-related in order to measure the influence of anxiety on checking. A version of the task without checking possibility was used to assess memory abilities.

Results

OCD checkers had similar memory performances but checked more than the other groups when presented with non-anxiogenic stimuli. Level of anxiety associated to the stimulus did not influence the number of checks.

Conclusions

Increased checking in OCD checkers, being independent of memory abilities and primary obsession-related anxiety, would, therefore, be closer to an automated behaviour than a coping strategy.

Responsibility and hand washing behaviour

BACKGROUND AND OBJECTIVES

Recent research suggests that compulsions persist due to a self-perpetuating mechanism of poor memory confidence and repetition. However, most of this work has examined checking compulsions and findings may not generalize well to washing compulsions. This study examined the role of responsibility in the persistence of washing behaviour.

METHODS

Hand washing was examined in undergraduates (n = 80) high and low in contamination fears (CF) under conditions of high or low responsibility (RL). Wash duration and number of visits to objects/locations key to the wash (e.g., soap) were examined.

RESULTS

Overvalued responsibility predicted washing duration across groups. Neither wash duration nor number of visits was associated with memory for the wash. Wash duration predicted post-wash certainty that the wash had prevented harm, but only in the high CF group, and that effect varied according to RL: longer wash duration predicted greater certainty under conditions of low RL but predicted less certainty under conditions of high RL. Greater repetition predicted poorer sensory confidence, but only in the high CF group under high RL conditions.

LIMITATIONS

The data were collected in an analogue sample of modest size. Replication in a clinical sample is required.

CONCLUSIONS

Self-perpetuating mechanisms identified in perseverative checking seem to also be present in perseverative washing, but only under conditions of high responsibility. Sensory confidence may be more important to perseverative washing than memory confidence. More research is required to understand self-perpetuating mechanisms at play when washing to under conditions of high responsibility.

Animal models of obsessive-compulsive disorder: utility and limitations

Obsessive-compulsive disorder (OCD) is a disabling and common neuropsychiatric condition of poorly known etiology. Many attempts have been made in the last few years to develop animal models of OCD with the aim of clarifying the genetic, neurochemical, and neuroanatomical basis of the disorder, as well as of developing novel pharmacological and neurosurgical treatments that may help to improve the prognosis of the illness. The latter goal is particularly important given that around 40% of patients with OCD do not respond to currently available therapies. This article summarizes strengths and limitations of the leading animal models of OCD including genetic, pharmacologically induced, behavioral manipulation-based, and neurodevelopmental models according to their face, construct, and predictive validity. On the basis of this evaluation, we discuss that currently labeled "animal models of OCD" should be regarded not as models of OCD but, rather, as animal models of different psychopathological processes, such as compulsivity, stereotypy, or perseverance, that are present not only in OCD but also in other psychiatric or neurological disorders. Animal models might constitute a challenging approach to study the neural and genetic mechanism of these phenomena from a trans-diagnostic perspective. Animal models are also of particular interest as tools for developing new therapeutic options for OCD, with the greatest convergence focusing on the glutamatergic system, the role of ovarian and related hormones, and the exploration of new potential targets for deep brain stimulation. Finally, future research on neurocognitive deficits associated with OCD through the use of analogous animal tasks could also provide a genuine opportunity to disentangle the complex etiology of the disorder.

Spatial behavior reflects the mental disorder in OCD patients with and without comorbid schizophrenia

OBJECTIVE

Resolving the entangled nosological dilemma of whether obsessive-compulsive disorder (OCD) with and without schizophrenia (schizo-OCD and OCD, respectively) are two independent entities or whether schizo-OCD is a combined product of its parent disorders.

METHODS

Studying motor activity in OCD and in schizo-OCD patients. Performance of the patients was compared with the performance of the same motor task by a matching control individual.

RESULTS

Behavior in both schizo-OCD and OCD patients differed from controls in the excessive repetition and addition of acts, thus validating an identical OC facet. However, there was a significant difference in spatial behavior. Schizo-OCD patients traveled over a greater area with less focused activity as typical to schizophrenia patients and in contrast to OCD patients, who were more focused and traveled less in a confined area. While schizo-OCD and OCD patients share most of the OC ritualistic attributes, they differ in the greater spread of activity in schizo-OCD, which is related to schizophrenia disorder.

DISCUSSION

It is suggested that the finding on difference in spatial behavior is a reflection of the mental differences between OCD and schizophrenia. In other words, this could be an overt and observable manifestation of the mental state, and therefore may facilitate the nosology of OC spectrum disorders and OCD.

CONCLUSION

It seems as if both the OCD patients' focus on specific thoughts, and the contrasting wandering thoughts of schizophrenia patients, are reflected in the focused activity of the former and wandering from one place to the next of the latter.

The impact of precaution and practice on the performance of a risky motor task

The association between threat perception and motor execution, mediated by evolved precaution systems, often results in ritual-like behavior, including many idiosyncratic acts that seem irrelevant to the task at hand. This study tested the hypothesis that threat-detection during performance of a risky motor task would result in idiosyncratic activity that is not necessary for task completion. We asked biology students to follow a particular set of instructions in mixing three solutions labeled "bio-hazardous" and then repeat this operation with "non-hazardous" substances (or vice versa). We observed a longer duration of the overall performance, a greater repertoire of acts, longer maximal act duration, and longer mean duration of acts in the "risky" task when it was performed before the "non-risky" task. Some, but not all, of these differences were eliminated when a "non-risky" task preceded the "risky" one. The increased performance of idiosyncratic unnecessary activity is in accordance with the working hypothesis of the present study: ritualized idiosyncratic activities are performed in response to a real or illusionary threat, as a means to alleviate anxiety.

Marked inbred mouse strain difference in the expression of quinpirole induced compulsive like behavior based on behavioral pattern analysis

Obsessive-compulsive disorder (OCD) is a chronic and complex psychiatric disorder with a lifetime prevalence of 2-3%. Recent work has shown that OCD rituals were not only characterized by a high rate of repetition but also by an increased behavioral repertoire due to additional non-functional unique acts. These two behavioral characteristics may provide an ethological basis for studying compulsive behavior in an animal model of OCD. Here, quinpirole induced behavior (so far only investigated in rats) has been studied in A/J and C57BL/6J mice by using behavioral pattern analysis. The aim of this study is to investigate whether genetic background is mediating this behavior. Results showed that open field motor activity levels of saline treated C57BL/6J mice was significantly higher compared to A/J treated saline mice. Long-term quinpirole treatment increased open field motor activity levels in A/J, but not in C57BL/6J. Quinpirole treatment induced a strain dependent difference in behavioral repertoire. There was a dose dependent increase in the number of different behavioral patterns in A/J, whereas, in C57BL/6J there was a dose dependent decrease. This data suggest that genetic background is important in expressing quinpirole induced compulsive like behavior. Following quinpirole treatment, A/J mice express a greater behavioral repertoire with a high rate of repetition. This phenotype resembles that of OCD rituals in patients and indicates that this strain is very interesting to further validate for studying neurobiological mechanisms of compulsive behavior.

Behavioral pattern analysis and dopamine release in quinpirole-induced repetitive behavior in rats

Obsessive-compulsive disorder (OCD) is a chronic and disabling psychiatric disease with a lifetime prevalence of 2-3%. People with OCD suffer from intrusive, unwanted and recurrent thoughts (obsessions) and/or repetitive ritualistic behaviors (compulsions). The aim of this study is to quantify the dimensions of ritualistic 'compulsive-like' behavior in quinpirole-induced behavior in rats by using T-pattern behavioral analysis. In addition, we investigated whether the behavioral effects elicited by quinpirole sensitization remained after 2 weeks of cessation of treatment. Finally, to study the neurobiological underpinnings of this 'compulsive-like' behavior, we investigated the effect of quinpirole treatment on the extracellular dopamine levels in the nucleus accumbens. Once established, 'compulsive-like' behavior is dependent upon quinpirole administration, as this behavior rapidly normalized after cessation of treatment. After a single dose of quinpirole the dopamine level decreased more in saline pre-treated animals as compared with animals given quinpirole treatment continuously. Furthermore, T-pattern analysis revealed that quinpirole-induced behavior consists, unlike OCD rituals, of a smaller behavioral repertoire. As seen in patients with OCD, quinpirole-treated animals performed these behaviors with a high rate of repetition. These findings suggest that quinpirole-induced behavior mimics only part of the compulsive behavior as shown in OCD patients.

Video telemetry and behavioral analysis discriminate between compulsive cleaning and compulsive checking in obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) patients exhibit compulsive acts that share key characteristics that discriminate them from normal behaviors. In OCD, factor analysis of symptomatology has identified separate clusters (contamination/cleaning; harming/checking; symmetry/ordering; hoarding). Here we used video analysis of the motor characteristics of OCD compulsions derived from two separate clusters, checking and cleaning, in order to determine whether behavioral differences exist in the way these two compulsions are performed. We compared 22 behavioral components (acts) of 12 OC-cleaning rituals and 25 OC-checking rituals. A normal activity with the identical theme was matched for each OC ritual as a control. For each ritual and control, we measured 22 parameters (such as the duration and frequency of act performance), and the levels of functionality, by evaluating the degree to which the act appears to contribute toward achieving its goal. We found that both OC-cleaning and OC-checking rituals differed from their respective control activity, and that they also differ between themselves in seven out of the 22 parameters. OC-cleaning involved increased repetition of functional activity whereas OC-checking involved a relatively increased non-functional activity. These results suggest that OCD cleaning and checking rituals are sufficiently different to justify their division into different subtypes and presumably are sub-served by different mechanisms. A better understanding of the relationship between those behavioral parameters derived from video-telemetry, and the parameters assessed by means of clinical and neurobiological tools, would improve our understanding of the nosological significance of compulsive symptoms and contribute to advancing endophenotypic exploration of the heterogeneity of OCD.

Manifestation of incompleteness in obsessive-compulsive disorder (OCD) as reduced functionality and extended activity beyond task completion

BACKGROUND

This study focused on hypotheses regarding the source of incompleteness in obsessive-compulsive disorder (OCD). For this, we had to document the behavioral manifestation of incompleteness in compulsive rituals, predicting that an exaggerated focus on acts that are appropriate for the task will support the hypothesis on heightened responsibility/perfectionism. In contrast, activity past the expected terminal act for the motor task would support the "stop signal deficiency" hypothesis.

METHODOLOGY AND PRINCIPAL FINDINGS

We employed video-telemetry to analyze 39 motor OCD rituals and compared each with a similar task performed by a non-OCD individual, in order to objectively and explicitly determine the functional end of the activity. We found that 75% of OCD rituals comprised a "tail," which is a section that follows the functional end of the task that the patients ascribed to their activity. The other 25% tailless rituals comprised a relatively high number and higher rate of repetition of non-functional acts. Thus, in rituals with tail, incompleteness was manifested by the mere presence of the tail whereas in tailless rituals, incompleteness was manifested by the reduced functionality of the task due to an inflated execution and repetition of non-functional acts.

CONCLUSIONS

The prevalence of activity after the functional end ("tail") and the elevated non-functionality in OCD motor rituals support the "lack of stop signal" theories as the underlying mechanism in OCD. Furthermore, the presence and content of the tail might have a therapeutic potential in cognitive-behavior therapy.

Repeated assessment of exploration and novelty seeking in the human behavioral pattern monitor in bipolar disorder patients and healthy individuals

Background

Exploration and novelty seeking are cross-species adaptive behaviors that are dysregulated in bipolar disorder (BD) and are critical features of the illness. While these behaviors have been extensively quantified in animals, multivariate human paradigms of exploration are lacking. The human Behavioral Pattern Monitor (hBPM), a human version of the animal open field, identified a signature pattern of hyper-exploration in manic BD patients, but whether exploratory behavior changes with treatment is unknown. The objective of this study was to assess the sensitivity of the hBPM to changes in manic symptoms, a necessary step towards elucidating the neurobiology underlying BD.

Methodology and Principal Findings

Twelve acutely hospitalized manic BD subjects and 21 healthy volunteers were tested in the hBPM over three sessions; all subjects were retested one week after their first session and two weeks after their second session. Motor activity, spatial and entropic (degree of unpredictability) patterns of exploration, and interactions with novel objects were quantified. Manic BD patients demonstrated greater motor activity, extensive and more unpredictable patterns of exploration, and more object interactions than healthy volunteers during all three sessions. Exploration and novelty-seeking slightly decreased in manic BD subjects over the three sessions as their symptoms responded to treatment, but never to the level of healthy volunteers. Among healthy volunteers, exploration did not significantly decrease over time, and hBPM measures were highly correlated between sessions.

Conclusions/Significance

Manic BD patients showed a modest reduction in symptoms yet still demonstrated hyper-exploration and novelty seeking in the hBPM, suggesting that these illness features may be enduring characteristics of BD. Furthermore, behavior in the hBPM is not subject to marked habituation effects. The hBPM can be reliably used in a repeated-measures design to characterize exploration and novelty seeking and, in parallel with animal studies, can contribute to developing treatments that target neuropsychiatric disease.

Dynamical principles of emotion-cognition interaction: mathematical images of mental disorders

The key contribution of this work is to introduce a mathematical framework to understand self-organized dynamics in the brain that can explain certain aspects of itinerant behavior. Specifically, we introduce a model based upon the coupling of generalized Lotka-Volterra systems. This coupling is based upon competition for common resources. The system can be regarded as a normal or canonical form for any distributed system that shows self-organized dynamics that entail winnerless competition. Crucially, we will show that some of the fundamental instabilities that arise in these coupled systems are remarkably similar to endogenous activity seen in the brain (using EEG and fMRI). Furthermore, by changing a small subset of the system's parameters we can produce bifurcations and metastable sequential dynamics changing, which bear a remarkable similarity to pathological brain states seen in psychiatry. In what follows, we will consider the coupling of two macroscopic modes of brain activity, which, in a purely descriptive fashion, we will label as cognitive and emotional modes. Our aim is to examine the dynamical structures that emerge when coupling these two modes and relate them tentatively to brain activity in normal and non-normal states.

Pragmatic and idiosyncratic acts in human everyday routines: the counterpart of compulsive rituals

Our daily activities are comprised of motor routines, which are behavioral templates with specific goals, typically performed in an automatic fixed manner and without much conscious attention. Such routines can seem to resemble pathologic rituals that dominate the motor behavior of obsessive-compulsive disorder (OCD) and autistic patients. This resemblance raises the question of what differentiates and what is common in normal and pathologic motor behavior. Indeed, pathologic motor performance is often construed as an extended stereotyped version of normal everyday routines. In this study we applied ethological tools to analyze six motor routines performed by 60 adult human volunteers. We found that longer normal everyday routines included more repetitions, but not more types of acts, and that in each routine, most acts were performed either by all individuals (pragmatic acts) or by only one individual (idiosyncratic components). Thus, normal routines consist in a relatively rigid part that is shared by all individuals that perform the routine, and a flexible part that varies among individuals. The present results, however, do not answer the question of whether the flexible individual part changes or remains constant over routine repetition by the same person. Comparing normal routines with OCD rituals revealed that the latter comprise an exaggeration of the idiosyncratic component. Altogether, the present study supports the view that everyday normal routines and pathologic rituals are opposite processes, although they both comprise rigid motor behavioral sequences.

A reverse-translational study of dysfunctional exploration in psychiatric disorders: from mice to men

CONTEXT

Bipolar mania and schizophrenia are recognized as separate disorders but share many commonalities, which raises the question of whether they are the same disorder on different ends of a continuum. The lack of distinct endophenotypes of bipolar mania and schizophrenia has complicated the development of animal models that are specific to these disorders. Exploration is fundamental to survival and is dysregulated in these 2 disorders. Although exploratory behavior in rodents has been widely studied, surprisingly little work has examined this critical function in humans.

OBJECTIVES

To quantify the exploratory behavior of individuals with bipolar mania and schizophrenia and to identify distinctive phenotypes of these illnesses.

DESIGN

Static group comparison by the use of a novel human open field paradigm, the human Behavioral Pattern Monitor (BPM).

SETTING

Psychiatric hospital.

PARTICIPANTS

Fifteen patients with bipolar mania and 16 patients with schizophrenia were compared with 26 healthy volunteers in the human BPM. The effects of amphetamine sulfate, the selective dopamine transporter inhibitor GBR12909, and the genetic knockdown of the dopamine transporter were compared with controls in the mouse BPM.

MAIN OUTCOME MEASURES

The amount of motor activity, spatial patterns of activity, and exploration of novel stimuli were quantified in both the human and mouse BPMs.

RESULTS

Patients with bipolar mania demonstrated a unique exploratory pattern, characterized by high motor activity and increased object exploration. Patients with schizophrenia did not show the expected habituation of motor activity. Selective genetic or pharmacologic inhibition of the dopamine transporter matched the mania phenotype better than the effects of amphetamine, which has been the criterion standard for animal models of mania.

CONCLUSIONS

These findings validate the human open field paradigm and identify defining characteristics of bipolar mania that are distinct from those of schizophrenia. This cross-species study of exploration calls into question an accepted animal model of mania and should help to develop more accurate human and animal models, which are essential to the identification of the neurobiological underpinnings of neuropsychiatric disorders.

Modulation of quinpirole-induced compulsive-like behavior in rats by environmental changes: implications for OCD rituals and for exploration and navigation

Background

Rats treated chronically with the D_2–3 dopamine agonist quinpirole were previously proposed as an animal model of obsessive-compulsive disorder (OCD) since their behavior is based on repeated, compulsive-like persistent traveling between a few places in the open field. The aim of the present study was to determine properties of the physical environment that shape such behavior. For this, quinpirole-treated rats were first exposed to an arena with an array of objects (landmarks) and after the development of compulsive-like behavior, the arena was manipulated by multiplying the number of objects, changing their spacing, relocating object array, or removing the objects.

Results

When the number of objects was retained but they were spaced further apart, rat routes converged at 1–2 of the objects and at the corner at which the rats had been introduced into the arena (start corner). When object spacing was retained but their number was increased, the rats traveled between the objects with the routes converging only at the start corner. Finally, when object array was relocated to different places within the arena, the rats extended their routes from the start corner to the object array, regardless of array location.

Conclusion

Quinpirole-treated rats organized and updated their progression primarily according to the proximal layout of landmarks, but did so with excessive repetitions compared with saline-treated rats. The behavior of quinpirole-treated rats paralleled human OCD rituals that are linked to the immediate physical environment, featuring an excessive rate of performance. Finally, when only a few objects were present, they were perceived by the rats as positional cues (beacons) that routes converged at them. In contrast, in the presence of many objects, the routes passed between the objects as if using them as directional cues.