Are nonclinical obsessive-compulsive symptoms associated with bias toward habits?

Cortico-striatal white-matter connectivity underlies the ability to exert goal-directed control

The balance between goal-directed and habitual control has been proposed to determine the flexibility of instrumental behaviour, in both humans and animals. This view is supported by neuroscientific studies that have implicated dissociable neural pathways in the ability to flexibly adjust behaviour when outcome values change. A previous Diffusion Tensor Imaging study provided preliminary evidence that flexible instrumental performance depends on the strength of parallel cortico-striatal white-matter pathways previously implicated in goal-directed and habitual control. Specifically, estimated white-matter strength between caudate and ventromedial prefrontal cortex correlated positively with behavioural flexibility, and posterior putamen-premotor cortex connectivity correlated negatively, in line with the notion that these pathways compete for control. However, the sample size of the original study was limited, and so far, there have been no attempts to replicate these findings. In the present study, we aimed to conceptually replicate these findings by testing a large sample of 205 young adults to relate cortico-striatal connectivity to performance on the slips-of-action task. In short, we found only positive neural correlates of goal-directed performance, including striatal connectivity (caudate and anterior putamen) with the dorsolateral prefrontal cortex. However, we failed to provide converging evidence for the existence of a neural habit system that puts limits on the capacity for flexible, goal-directed action. We discuss the implications of our findings for dual-process theories of instrumental action.

Assessing biomarkers of remission in female patients with anorexia nervosa (REMANO): a protocol for a prospective cohort study with a nested case-control study using clinical, neurocognitive, biological, genetic, epigenetic and neuroimaging markers in a French specialised inpatient unit

BACKGROUND

Anorexia nervosa (AN) is a severe psychiatric disorder associated with frequent relapses and variability in treatment responses. Previous literature suggested that such variability is influenced by premorbid vulnerabilities such as abnormalities of the reward system. Several factors may indicate these vulnerabilities, such as neurocognitive markers (tendency to favour delayed reward, poor cognitive flexibility, abnormal decision process), genetic and epigenetic markers, biological and hormonal markers, and physiological markers.The present study will aim to identify markers that can predict body mass index (BMI) stability 6 months after discharge. The secondary aim of this study will be focused on characterising the biological, genetic, epigenetic and neurocognitive markers of remission in AN.

METHODS AND ANALYSIS

One hundred and twenty-five (n=125) female adult inpatients diagnosed with AN will be recruited and evaluated at three different times: at the beginning of hospitalisation, when discharged and 6 months later. Depending on the BMI at the third visit, patients will be split into two groups: stable remission (BMI≥18.5 kg/m²) or unstable remission (BMI<18.5 kg/m²). One hundred (n=100) volunteers will be included as healthy controls.Each visit will consist in self-reported inventories (measuring depression, anxiety, suicidal thoughts and feelings, eating disorders symptoms, exercise addiction and the presence of comorbidities), neurocognitive tasks (Delay Discounting Task, Trail-Making Test, Brixton Test and Slip-of-action Task), the collection of blood samples, the repeated collection of blood samples around a standard meal and MRI scans at rest and while resolving a delay discounting task.Analyses will mainly consist in comparing patients stabilised 6 months later and patients who relapsed during these 6 months.

ETHICS AND DISSEMINATION

Investigators will ask all participants to give written informed consent prior to participation, and all data will be recorded anonymously. The study will be conducted according to ethics recommendations from the Helsinki declaration (World Medical Association, 2013). It was registered on clinicaltrials.gov on 25 August 2020 as 'Remission Factors in Anorexia Nervosa (REMANO)', with the identifier NCT04560517 (for more details, see https://clinicaltrials.gov/ct2/show/record/NCT04560517). The present article is based on the latest protocol version from 29 November 2019. The sponsor, Institut National de la Santé Et de la Recherche Médicale (INSERM, https://www.inserm.fr/), is an academic institution responsible for the monitoring of the study, with an audit planned on a yearly basis.The results will be published after final analysis in the form of scientific articles in peer-reviewed journals and may be presented at national and international conferences.

TRIAL REGISTRATION NUMBER

clinicaltrials.govNCT04560517.

A novel free-operant framework enables experimental habit induction in humans

Habits are a prominent feature of both adaptive and maladaptive behavior. Yet, despite substantial research efforts, there are currently no well-established experimental procedures for habit induction in humans. It is likely that laboratory experimental settings, as well as the session-based structure typically used in controlled experiments (also outside the lab), impose serious constraints on studying habits and other effects that are sensitive to context, motivation, and training duration and frequency. To overcome these challenges, we devised a unique real-world free-operant task structure, implemented through a novel smartphone application, whereby participants could freely enter the app (24 hours a day, 7 days a week) to win rewards. This procedure is free of typical laboratory constraints, yet well controlled. Using the canonical sensitivity to outcome devaluation criterion, we successfully demonstrated habit formation as a function of training duration, a long-standing challenge in the field. Additionally, we show a positive relationship between multiple facets of engagement/motivation and goal-directedness. We suggest that our novel paradigm can be used to study the neurobehavioral and psychological mechanism underlying habits in humans. Moreover, the real-world free-operant framework can potentially be used to examine other instrumental behavior-related questions, with greater face validity in naturalistic conditions.

Associations between nesting, stereotypy, and working memory in deer mice: response to levetiracetam

BACKGROUND

Some deer mice (Peromyscus maniculatus bairdii) exhibit various phenotypes of persistent behaviors. It remains unknown if and how said phenotypes associate with early-life and adult cognitive perturbations, and whether potentially cognitive enhancing drugs might modify such associations. Here, we explored the longitudinal relationship between early-life behavioral flexibility and the expression of persistent behavior in adulthood. We also investigated how said phenotypes might associate with working memory in adulthood, and how this association might respond to chronic exposure to the putative cognitive enhancer, levetiracetam (LEV).

METHODS

76 juvenile deer mice were assessed for habit-proneness in the Barnes maze (BM) and divided into two exposure groups (n = 37-39 per group), i.e., control and LEV (75 mg/kg/day). After 56 days of uninterrupted exposure, mice were screened for nesting and stereotypical behavior, and then assessed for working memory in the T-maze.

RESULTS

Juvenile deer mice overwhelmingly utilize habit-like response strategies, regardless of LNB and HS behavior in adulthood. Further, LNB and HS are unrelated in terms of their expression, while LEV reduces the expression of LNB, but bolsters CR (but not VA). Last, an increased level of control over high stereotypical expression may facilitate improved working memory performance.

CONCLUSION

LNB, VA and CR, are divergent in terms of their neurocognitive underpinnings. Chronic LEV administration throughout the entire rearing period may be of benefit to some phenotypes, e.g., LNB, but not others (CR). We also show that an increased level of control over the expression of stereotypy may facilitate improved working memory performance.

Impaired belief updating and devaluation in adult women with bulimia nervosa

Recent models of bulimia nervosa (BN) propose that binge-purge episodes ultimately become automatic in response to cues and insensitive to negative outcomes. Here, we examined whether women with BN show alterations in instrumental learning and devaluation sensitivity using traditional and computational modeling analyses of behavioral data. Adult women with BN (n = 30) and group-matched healthy controls (n = 31) completed a task in which they first learned stimulus-response-outcome associations. Then, participants were required to repeatedly adjust their responses in a "baseline test", when different sets of stimuli were explicitly devalued, and in a "slips-of-action test", when outcomes instead of stimuli were devalued. The BN group showed intact behavioral sensitivity to outcome devaluation during the slips-of-action test, but showed difficulty overriding previously learned stimulus-response associations on the baseline test. Results from a Bayesian learner model indicated that this impaired performance could be accounted for by a slower pace of belief updating when a new set of previously learned responses had to be inhibited (p = 0.036). Worse performance and a slower belief update in the baseline test were each associated with more frequent binge eating (p = 0.012) and purging (p = 0.002). Our findings suggest that BN diagnosis and severity are associated with deficits in flexibly updating beliefs to withhold previously learned responses to cues. Additional research is needed to determine whether this impaired ability to adjust behavior is responsible for maintaining automatic and persistent binge eating and purging in response to internal and environmental cues.

Subjective reward processing and catechol-O- methyltransferase Val158Met polymorphism as potential research domain criteria in addiction: A pilot study

The Research Domain Criteria (RDoC) approach seeks to understand mental functioning in continuous valid dimensions ranging from functional to pathological. Reward processing is a transdiagnostic functioning domain of the RDoC. Due to prototypical abnormalities, addictions are especially applicable for the investigation of reward processing. Subjective reward processing is challenging to determine and differs between genotypes of the catechol-O-methyltransferase gene (COMT) Val158Met polymorphism for incomparable daily life experiences. Thus, we implemented the monetary incentive delay (MID) task with comparable reward cues and visual analog scales (VAS) to assess subjective reward processing in male abstinent cannabis-dependent individuals (N = 13) and a control group of nicotine smokers (N = 13). COMT Val158Met genotypes were nominally associated with differences in cigarettes smoked per day and motivation in the MID Task (p = 0.028; p = 0.017). For feedback gain, activation of the right insula was increased in controls, and activation correlated with gain expectancy and satisfaction about gain. Subjective value is not detached from reward parameters, but is modulated from expectancy and reward by the insula. The underlying neural mechanisms are a fundamental target point for treatments, interventions, and cognitive behavioral therapy.

Determining the effects of training duration on the behavioral expression of habitual control in humans: a multilaboratory investigation

It has been suggested that there are two distinct and parallel mechanisms for controlling instrumental behavior in mammals: goal-directed actions and habits. To gain an understanding of how these two systems interact to control behavior, it is essential to characterize the mechanisms by which the balance between these systems is influenced by experience. Studies in rodents have shown that the amount of training governs the relative expression of these two systems: Behavior is goal-directed following moderate training, but the more extensively an instrumental action is trained, the more it becomes habitual. It is less clear whether humans exhibit similar training effects on the expression of goal-directed and habitual behavior, as human studies have reported contradictory findings. To tackle these contradictory findings, we formed a consortium, where four laboratories undertook a preregistered experimental induction of habits by manipulating the amount of training. There was no statistical evidence for a main effect of the amount of training on the formation and expression of habits. However, exploratory analyses suggest a moderating effect of the affective component of stress on the impact of training over habit expression. Participants who were lower in affective stress appeared to be initially goal-directed, but became habitual with increased training, whereas participants who were high in affective stress were already habitual even after moderate training, thereby manifesting insensitivity to overtraining effects. Our findings highlight the importance of the role of moderating variables such as individual differences in stress and anxiety when studying the experimental induction of habits in humans.

Model-Based Planning Deficits in Compulsivity Are Linked to Faulty Neural Representations of Task Structure

Compulsive individuals have deficits in model-based planning, but the mechanisms that drive this have not been established. We examined two candidates-that compulsivity is linked to (1) an impaired model of the task environment and/or (2) an inability to engage cognitive control when making choices. To test this, 192 participants performed a two-step reinforcement learning task with concurrent EEG recordings, and we related the neural and behavioral data to their scores on a self-reported transdiagnostic dimension of compulsivity. To examine subjects' internal model of the task, we used established behavioral and neural responses to unexpected events [reaction time (RT) slowing, P300 wave, and parietal-occipital alpha band power] measured when an unexpected transition occurred. To assess cognitive control, we probed theta power at the time of initial choice. As expected, model-based planning was linked to greater behavioral (RT) and neural (alpha power, but not P300) sensitivity to rare transitions. Critically, the sensitivities of both RT and alpha to task structure were weaker in those high in compulsivity. This RT-compulsivity effect was tested and replicated in an independent pre-existing dataset (N = 1413). We also found that mid-frontal theta power at the time of choice was reduced in highly compulsive individuals though its relation to model-based planning was less pronounced. These data suggest that model-based planning deficits in compulsive individuals may arise, at least in part, from having an impaired representation of the environment, specifically how actions lead to future states.SIGNIFICANCE STATEMENT Compulsivity is linked to poorer performance on tasks that require model-based planning, but it is unclear what precise mechanisms underlie this deficit. Do compulsive individuals fail to engage cognitive control at the time of choice? Or do they have difficulty in building and maintaining an accurate representation of their environment, the foundation needed to behave in a goal-directed manner? With reaction time and EEG measures in 192 individuals who performed a two-step decision-making task, we found that compulsive individuals are less sensitive to surprising action-state transitions, where they slow down less and show less alpha band suppression following a rare transition. These findings implicate failures in maintaining an accurate model of the world in model-based planning deficits in compulsivity.

Brain Functional Connectivity Correlates of Subclinical Obsessive-Compulsive Symptoms in Healthy Children

OBJECTIVE

Commonly observed subclinical obsessive-compulsive symptoms in healthy children may predispose to obsessive-compulsive disorder (OCD). Therefore, investigating the underlying neurobiology may be relevant to identify alterations in specific brain circuits potentially accounting for clinical heterogeneity in OCD without the confounding effects of clinical samples. We analyzed the brain correlates of different obsessive-compulsive symptoms in a large group of healthy children using functional connectivity measures.

METHOD

We evaluated 227 healthy children (52% girls; mean [SD] age 9.71 [0.86] years; range, 8-12.1 years). Participants underwent clinical assessment with the Obsessive-Compulsive Inventory-Child Version and a resting-state functional magnetic resonance imaging examination. Total and symptom-specific severity were correlated with voxelwise global functional connectivity degree values. Significant clusters were then used as seeds of interest in seed-to-voxel analyses. Modulating effects of age and sex were also assessed.

RESULTS

Global functional connectivity of the left ventral putamen and medial dorsal thalamus correlated negatively with total obsessive-compulsive symptom severity. Seed-to-voxel analyses revealed specific negative correlations from these clusters with limbic, sensorimotor, and insular regions in association with obsessing, ordering, and doubt-checking symptoms, respectively. Hoarding symptoms were associated with negative correlations between the left medial dorsal thalamus and a widespread pattern of regions, with such associations modulated by sex and age.

CONCLUSION

Our findings concur with prevailing neurobiological models of OCD on the importance of cortico-striato-thalamo-cortical dysfunction to account for symptom severity. Notably, we showed that changes in cortico-striato-thalamo-cortical connectivity are present at subclinical stages, which may result in an increased vulnerability for OCD. Moreover, we mapped different symptom dimensions onto specific cortico-striato-thalamo-cortical circuit attributes.

Early-life stress is associated with a preponderance of habitual responding in a novel instrumental avoidance learning paradigm

There is substantial evidence linking early-life stress (ELS) to negative health outcomes in adulthood, including addiction. However, the neurocognitive and behavioral mechanisms through which ELS increases these risks remain unclear. To address this gap in knowledge, we developed a novel instrumental learning paradigm to explore the effects of ELS on the balance of habitual versus goal-directed learning. Habits efficiently reproduce repetitive behaviors but are inflexible whenreward contingencies related to those behaviors change. Persisting in performing a response after its outcome has been devalued is the hallmark of habitual behavior in instrumental learning. Participants with a history of higher ELS were significantly more likely to make habitual responses in this instrumental avoidance learning paradigm than individuals with a history of lower ELS. Logistic regression analysis showed that ELS is significantly related to habitual responding over and above the effects of retrospective socioeconomic status, trait and state anxiety, depression and recent levels of stress. Analysis of the differential impacts of the type of ELS suggested that these effects are largely driven by experiences of physical neglect.

A Test of the Habit-Goal Framework of Depressive Rumination and Its Relevance to Cognitive Reactivity

The aim of the present study was to test predictions derived from the habit-goal framework of depressive rumination and investigate its relevance to cognitive reactivity-another well-known vulnerability factor to depression. Formerly depressed (FD; n=20) and never depressed (ND; n=22) participants completed self-report measures of rumination, cognitive reactivity, and habitual characteristics of rumination (e.g., lack of awareness, control, intent). A standard mood-induction task was also used to measure cognitive reactivity and an outcome-devaluation task to measure general habit vs. goal-directed behavior control. Habitual characteristics of ruminative thoughts were greater in the FD group and were related to depressive brooding and cognitive reactivity, but not reflective pondering. Reliance on habit on the outcome-devaluation task was strongly correlated with number of depression episodes, although group differences were not observed in general habit vs. goal-directed control. Habitual characteristics of rumination (e.g., greater automaticity) may explain reactivity and persistence of negative thoughts in depression. Habitual behavior control may contribute to inflexible responding and vulnerability for depression episodes.

Transdiagnostic Phenotyping Reveals a Host of Metacognitive Deficits Implicated in Compulsivity

Recent work suggests that obsessive-compulsive disorder (OCD) patients have a breakdown in the relationship between explicit beliefs (i.e. confidence about states) and updates to behaviour. The precise computations underlying this disconnection are unclear because case-control and transdiagnostic studies yield conflicting results. Here, a large online population sample (N = 437) completed a predictive inference task previously studied in the context of OCD. We tested if confidence, and its relationship to action and environmental evidence, were specifically associated with self-reported OCD symptoms or common to an array of psychiatric phenomena. We then investigated if a transdiagnostic approach would reveal a stronger and more specific match between metacognitive deficits and clinical phenotypes. Consistent with prior case-control work, we found that decreases in action-confidence coupling were associated with OCD symptoms, but also 5/8 of the other clinical phenotypes tested (8/8 with no correction applied). This non-specific pattern was explained by a single transdiagnostic symptom dimension characterized by compulsivity that was linked to inflated confidence and several deficits in utilizing evidence to update confidence. These data highlight the importance of metacognitive deficits for our understanding of compulsivity and underscore how transdiagnostic methods may prove a more powerful alternative over studies examining single disorders.

Instrumental learning in a mouse model for obsessive-compulsive disorder: Impaired habit formation in Sapap3 mutants

It has been hypothesized that maladaptive habit formation contributes to compulsivity in psychiatric disorders such as obsessive-compulsive disorder (OCD). Here, we used an established animal model of OCD, Sapap3 knockout mice (SAPAP3^-/-), to investigate the balance of goal-directed and habitual behavior in compulsive individuals and if altered habit formation is associated with compulsive-like behavior. We subjected 24 SAPAP3^-/- and 24 wildtype littermates (WT) to two different schedules of reinforcement in a within-subjects design: a random-ratio (RR) schedule to promote goal-directedness, and a random-interval (RI) schedule, known to facilitate habitual responding. SAPAP3^-/- acquired responding under both schedules, but showed lower response rates and fewer attempts to collect food pellets than WT, indicative of altered reward processing. As expected, WT were sensitive to sensory-specific satiety (outcome devaluation) following RR training, but not RI training, demonstrating schedule-specific acquisition of goal-directed and habitual responding, respectively. In contrast, SAPAP3^-/- were sensitive to outcome devaluation after both RR and RI training, suggesting decreased engagement of a habitual response strategy. No linear relation was observed between increased grooming and behavior during the outcome devaluation test in SAPAP3^-/-. Together, our findings demonstrate altered reward processing and impaired habit learning in SAPAP3^-/-. We report a diminished propensity to form habits in these mice, which albeit inconsistent with the predominant idea of excessive habit formation in OCD, nonetheless points at dysregulation of behavioral automation in the context of compulsivity. Thus, the habit hypothesis of compulsivity should be updated to state that an imbalance of habitual and goal-directed responding in either direction can contribute to the development of compulsive behavior.

Does cognitive-behavioral therapy affect goal-directed planning in obsessive-compulsive disorder?

Cross-sectional studies have reported failures in goal-directed planning in obsessive-compulsive disorder (OCD). It remains unclear whether these deficits confer vulnerability to developing OCD, or are a consequence of symptoms. The present study examined goal-directed learning before and after cognitive behavioral therapy (CBT), using treatment as a tool to reduce symptoms. Eighteen adult OCD patients undergoing 17 sessions of CBT completed an established task of model-based (i.e., goal directed) versus model-free planning as well as measures of OCD and depression before and after treatment. We thus tested whether improvements in goal-directed performance accompany improvements in OCD symptoms or if instead task performance remains stable despite symptom improvement. Results showed prior to treatment, higher OCD severity was associated with greater deficits in model-based planning. OCD severity scores significantly improved from pre- to post-treatment. Inconsistent with the state-view, OCD symptom improvement was not accompanied by improvements in model-based performance. At post-treatment, OCD severity scores were no longer correlated with model-based performance. Together, these data suggest that reducing OCD symptoms with CBT does not affect goal-directed planning. This supports a trait model of the relationship between goal-directed planning and OCD symptoms, such that problems in goal-directed planning may be an OCD risk factor.

Obsessive-compulsive disorder comorbid with schizophrenia and bipolar disorder

Obsessive Compulsive Disorder (OCD) and Obsessive Compulsive Symptoms (OCS) are known to be highly comorbid with bipolar disorder and schizophrenia. Comorbid OCD/OCS influences the course of schizophrenia and bipolar disorder. There is also some evidence to suggest that a diagnosis of OCD may be associated with elevated risk for later development of psychosis and bipolar disorder. Comorbid OCD/OCS is associated with a greater severity of schizophrenia phenotype and poorer prognosis. In addition, certain atypical antipsychotics, clozapine in particular are known to induce or worsen OCS in schizophrenia. OCD when comorbid with bipolar disorder mostly runs an episodic course with worsening and improvement of OCD/OCS in depressive and in manic/hypomanic phases respectively. There is limited systematic data on the treatment of OCD in schizophrenia and bipolar disorder. When OCD presents in the context of schizophrenia, management may include treatment with atypical antipsychotics with limited serotonergic properties, changing the antipsychotic, reduction in the dose of the antipsychotic, addition of cognitive-behavior therapy (CBT), or a specific serotonin reuptake inhibitor (SSRI). When OCD is comorbid with bipolar disorder, mood stabilization is the priority. CBT may be preferred over SSRIs to treat OCD/OCS that persist in between the mood episodes because SSRIs may induce a switch or worsen the course of bipolar disorder. SSRIs when indicated have to be used judiciously under the cover of adequate mood stabilization.

Conflicted between Goal-Directed and Habitual Control, an fMRI Investigation

“Slips of action” occur in everyday life when we momentarily lose sight of a goal (for example, when in a rush or distracted). Associative models propose that these habitual responses can be activated via a direct stimulus-response (S-R) mechanism, regardless of the current hedonic value of the outcome. The slips-of-action task (SOAT) has been extensively used in both healthy and pathological populations to measure habit tendencies, the likelihood of making erroneous responses for devalued outcomes. Inspection of behavioral performance does not reveal, however, whether the impairments were due to impaired goal-directed control or aberrantly strong habit formation. In the current study, we used functional MRI while human participants performed both the instrumental training and SOAT test phases, to elucidate the relative contributions of these mechanisms to performance on the SOAT. On trials in which conflict arises between competing goal-directed and habitual responses, we observed increased activation across areas including the anterior cingulate cortex, paracingulate gyrus, lateral orbitofrontal cortex (OFC), insula, and inferior frontal gyrus (IFG). Responding for devalued outcomes was related to increased activation in the premotor cortex and cerebellum, implicating these regions in habitual responding. Increased activation in the caudate, dorsolateral prefrontal cortex (dlPFC), and frontal pole during training was associated with better performance during the test phase, indicative of goal-directed action control. These results endorse interpretation of the SOAT in terms of competing goal-directed and habitual mechanisms and highlight that cognitive control processes present an additional bottleneck for successful performance on this task.

Investigating the balance between goal-directed and habitual control in experimental and real-life settings

Do people differ in their propensity to form habits? The current study related individual differences in habitual performance on the slips-of-action task to habit formation in real life. To this end, we developed a novel key-cover procedure that controls for the amount of repetition and motivation within a naturalistic setting. Participants received a key cover for the key to their home, which after several weeks was switched with a key cover that was previously attached to a dummy key. Participants recorded effort, time, attention, and mistakes in the key-selection process. Results were in line with established properties of habits, as attention decreased in the learning phase, yet effort, time, and mistakes increased after the key-cover switch. Performance on the slips-of-action task correlated negatively with changes in attention in the real-life key-cover task. This negative correlation may reflect that flexible behavioral adjustment requires more attention in people with a relatively weak goal-directed system.

Shifting the balance between goals and habits: Five failures in experimental habit induction

Habits are repetitive behaviors that become ingrained with practice, routine, and repetition. The more we repeat an action, the stronger our habits become. Behavioral and clinical neuroscientists have become increasingly interested in this topic because habits may contribute to aspects of maladaptive human behavior, such as compulsive behavior in psychiatry. Numerous studies have demonstrated that habits can be induced in otherwise healthy rats by simply overtraining stimulus-response behaviors. However, despite growing interest in this topic and its application to psychiatry, a similar body of work in humans is absent. Only a single study has been published in humans that shows the effect of extensive training on habit expression. Here, we report five failed attempts to demonstrate that overtraining instrumental behavior leads to the development of inflexible habits in humans, using variants of four previously published outcome devaluation paradigms. Extensive training did not lead to greater habits in two versions of an avoidance learning task, in an appetitive slips-of-action task, or in two independent attempts to replicate the original demonstration. The finding that these outcome devaluation procedures may be insensitive to duration of stimulus-response training in humans has implications for prior work in psychiatric populations. Specifically, it converges with the suggestion that the failures in outcome devaluation in compulsive individuals reflect dysfunction in goal-directed control, rather than overactive habit learning. We discuss why habits are difficult to experimentally induce in healthy humans, and the implications of this for future research in healthy and disordered populations. (PsycINFO Database Record

Relationship of obsessive-compulsive symptoms to clinical variables and cognitive functions in individuals at ultra high risk for psychosis

Few studies have investigated the relationship between obsessive-compulsive symptoms (OCS) and clinical variables, and cognition in individuals at ultra high-risk (UHR) for psychosis. The aim of this study was to evaluate the frequency of OCS and their relationship with clinical variables and cognitive functions in individuals at UHR. Eighty-four individuals at UHR for psychosis were administered the Brief Psychiatric Rating Scale, the Yale-Brown Obsession Compulsion Symptom Check List and, the Calgary Depression Scale for Schizophrenia. A cognitive test battery was also applied. We compared the clinical, functional, and cognitive parameters of individuals at UHR with and without OCS and healthy controls. Thirty-five percent of the UHR sample had at least two obsessions/compulsions. The duration of subthreshold psychotic symptoms was longer in individuals with OCS. Those who can work/study before first presentation were more frequent in OCS-positive group. CDSS scores were higher in those with OCS. Compared to controls, OCS-negative group's performance was worse in 8 cognitive test items, while OCS-positive group performed worse in only one cognitive test item. Our findings suggest that OCS are common in the UHR group. OCS might be related to higher level of depression, but better work/study performance, and less cognitive deficits in UHR group.

Brain Structural Correlates of Subclinical Obsessive-Compulsive Symptoms in Healthy Children

OBJECTIVE

Subclinical obsessive-compulsive (OC) symptoms are frequently observed in children and have been reported to predict a subsequent diagnosis of OC disorder (OCD). Therefore, identifying the putative neurobiological signatures of such risk is crucial, because it would allow for the characterization of the underpinnings of OCD without the interfering effects of chronicity, medication, or comorbidities, especially when interpreted within the context of OCD clinical heterogeneity and taking into account normal neurodevelopmental changes. The present study aimed to identify the brain volumetric features associated with subclinical OC symptoms and the potential modulatory effects of sex and age in a large sample of healthy children.

METHOD

Two hundred fifty-five healthy children were assessed using the Obsessive-Compulsive Inventory-Child Version and underwent a brain structural magnetic resonance examination. The relation between total and symptom-specific scores and regional gray and white matter (GM and WM) volumes was evaluated. Participants were grouped according to sex and age (younger versus older) to assess the effect of these factors on symptom-brain morphometry associations.

RESULTS

Ordering symptoms were negatively related to GM volumes in the ventral caudate. Hoarding symptoms were positively associated with GM and WM volumes in the left inferior frontal gyrus, and obsessing symptoms correlated negatively with GM and WM volumes in the right temporal pole. Doubt-checking symptoms correlated positively with WM volumes in the right inferior fronto-occipital fasciculus and the corpus callosum. Sex and age modulated some of these associations.

CONCLUSION

Subclinical OC symptoms are associated with specific brain volumetric features, which could be considered potential neural signatures of increased risk for OCD.

A trans-diagnostic perspective on obsessive-compulsive disorder

Progress in understanding the underlying neurobiology of obsessive-compulsive disorder (OCD) has stalled in part because of the considerable problem of heterogeneity within this diagnostic category, and homogeneity across other putatively discrete, diagnostic categories. As psychiatry begins to recognize the shortcomings of a purely symptom-based psychiatric nosology, new data-driven approaches have begun to be utilized with the goal of solving these problems: specifically, identifying trans-diagnostic aspects of clinical phenomenology based on their association with neurobiological processes. In this review, we describe key methodological approaches to understanding OCD from this perspective and highlight the candidate traits that have already been identified as a result of these early endeavours. We discuss how important inferences can be made from pre-existing case-control studies as well as showcasing newer methods that rely on large general population datasets to refine and validate psychiatric phenotypes. As exemplars, we take 'compulsivity' and 'anxiety', putatively trans-diagnostic symptom dimensions that are linked to well-defined neurobiological mechanisms, goal-directed learning and error-related negativity, respectively. We argue that the identification of biologically valid, more homogeneous, dimensions such as these provides renewed optimism for identifying reliable genetic contributions to OCD and other disorders, improving animal models and critically, provides a path towards a future of more targeted psychiatric treatments.

General Habit Propensity Relates to the Sensation Seeking Subdomain of Impulsivity But Not Obesity

According to dual-system theory, instrumental learning and performance depend on the balance between goal-directed and habitual action control. Overreliance on habits has been argued to characterize clinical conditions such as drug addiction or obsessive-compulsive disorder as well as obesity and excessive impulsivity. A tendency toward habitual action control in obesity has already been indicated in the food domain. However, impairments might not be restricted to eating behavior. This has been suggested by domain-general obesity-associated disturbances in executive function as well as alterations in corticostriatal circuits underlying the goal-directed and habitual systems. In this study we examined the balance of goal-directed and habitual action control in a sample of normal-weight, overweight, and obese participants (n = 105) using the slips-of-action test in a non-food context. We tested for continuous or group-based associations between body weight status (BMI) and the devaluation sensitivity index (DSI), a parameter representing the balance of the goal-directed and habitual systems in action control. As personality differences in the domain of impulsivity might affect this relationship, we also examined whether the interaction between BMI and self-reported impulsivity, based on the UPPS Impulsive Behavior Scale, was related to the DSI. In addition to that, we tested for direct, i.e., weight status independent, relationships between UPPS subdomains of impulsivity and the DSI. We failed to find evidence for a relationship between weight status and sensitivity to devaluation as indexed by the DSI. However, independent of weight status, we observed lower sensitivity to devaluation in sensation seekers, a subtype of impulsivity. To conclude, behavioral flexibility in the sense of disturbances in the balance between the habitual and goal-directed systems seems to be unaffected by weight status in a non-food context. Consequently, stimuli and behavior might not be generally excessively linked in overweight or obesity. However, according to ceiling effects we cannot rule out subtle effects the paradigm was not able to disentangle. Further, future studies are needed to clarify the role of specific subtypes of obesity (e.g., food addiction). The indicated habit propensity in sensation seekers may account for previous reports of weak avoidance behavior and risky decision making.