Obsessive compulsive disorder and basal ganglia dysfunction

No Impaired Inhibition of Stimulus-Driven Behavior in Pediatric Obsessive-Compulsive Disorder: a Partial Test of the Habit Formation Model

The mechanisms that underlie obsessive-compulsive disorder (OCD) are elusive. The habit formation model of OCD postulates that compulsions arise from an imbalance between goal-directed and habit formation systems, stemming from impaired inhibition of stimulus-driven actions. Few studies have examined the core tenets of the habit formation model in pediatric OCD. We administered the object-interference task, which assesses the ability to inhibit stimulus-driven behavior, to 67 youths with OCD, 43 youths with an anxiety disorder (and no OCD), and 48 youths without any mental disorder. Impaired inhibition of stimulus-driven behavior was calculated by comparing response times to neutral non-nameable objects, neutral nameable objects, distress-eliciting objects, and incompleteness-eliciting objects. Youths with OCD did not differ significantly from youths with anxiety disorders and the non-clinical group on any response cost measure. All groups showed small response costs in relation to all three categories of non-neutral objects, with the clearest cost emerging in relation to distress-eliciting objects. Individual differences in response cost were not significantly correlated with any interview- or self-rated measure of OCD severity. Using the object-interference task, no evidence was found for impaired inhibition of stimulus-driven behavior in youths with OCD. We explore several possible interpretations of this result, including limitations of the task itself, the broader constraints of experimental methods in detecting such mechanisms, and the possibility that an imbalance between goal-directed and habit systems may not be a fundamental feature of pediatric OCD.

Embracing variability in the search for biological mechanisms of psychiatric illness

Despite decades of research, we lack objective diagnostic or prognostic biomarkers of mental health problems. A key reason for this limited progress is a reliance on the traditional case-control paradigm, which assumes that each disorder has a single cause that can be uncovered by comparing average phenotypic values of patient and control samples. Here, we discuss the problematic assumptions on which this paradigm is based and highlight recent efforts that seek to characterize, rather than minimize, the inherent clinical and biological variability that underpins psychiatric populations. Embracing such variability is necessary to understand pathophysiological mechanisms and develop more targeted and effective treatments.

Early-onset obsessive-compulsive disorder: Sociodemographic and clinical characterization of a large outpatient cohort

INTRODUCTION

Obsessive-compulsive disorder (OCD) is a prevalent and disabling condition characterized by a wide variety of phenotypic expressions. Several studies have reinforced the hypothesis of OCD heterogeneity by proposing subtypes based on predominant symptomatology, course, and comorbidities. Early-onset OCD (EO) could be considered a neurodevelopmental subtype of OCD, with evidence of distinct neurocircuits supporting disease progression. To deepen the heterogeneous nature of the disorder, we analyzed sociodemographic and clinical differences between the EO and late-onset (LO) subtypes in a large outpatient cohort.

METHODS

Two hundred and eighty-four patients diagnosed with OCD were consecutively recruited from the OCD Tertiary Clinic at Luigi Sacco University Hospital in Milan. Sociodemographic and clinical variables were analyzed for the entire sample and compared between the two subgroups (EO, age <18 years [n = 117,41.2 %]; LO: late-onset, age ≥18 years [n = 167, 58.8 %]).

RESULTS

The EO group showed a higher frequency of male gender (65 % vs 42.5 %, p < .001), and a higher prevalence of Tic and Tourette disorders (9.4 % vs 0 %, p < .001) compared to the LO group. Additionally, in the EO subgroup, a longer duration of untreated illness was observed (9.01 ± 9.88 vs 4.81 ± 7.12; p < .001), along with a lower presence of insight (13.8 % vs. 7.5 %, p < .05).

CONCLUSIONS

The early-onset OCD subtype highlights a more severe clinical profile compared to the LO group. Exploring distinct manifestations and developmental trajectories of OCD can contribute to a better definition of homogeneous subtypes, useful for defining targeted therapeutic strategies for treatment.

Revisiting deficits in threat and safety appraisal in obsessive-compulsive disorder

Current behavioural treatment of obsessive-compulsive disorder (OCD) is informed by fear conditioning and involves iteratively re-evaluating previously threatening stimuli as safe. However, there is limited research investigating the neurobiological response to conditioning and reversal of threatening stimuli in individuals with OCD. A clinical sample of individuals with OCD (N = 45) and matched healthy controls (N = 45) underwent functional magnetic resonance imaging. While in the scanner, participants completed a well-validated fear reversal task and a resting-state scan. We found no evidence for group differences in task-evoked brain activation or functional connectivity in OCD. Multivariate analyses encompassing all participants in the clinical and control groups suggested that subjective appraisal of threatening and safe stimuli were associated with a larger difference in brain activity than the contribution of OCD symptoms. In particular, we observed a brain-behaviour continuum whereby heightened affective appraisal was related to increased bilateral insula activation during the task (r = 0.39, pFWE  = .001). These findings suggest that changes in conditioned threat-related processes may not be a core neurobiological feature of OCD and encourage further research on the role of subjective experience in fear conditioning.

Sex matters: The impact of oxytocin on healthy conditions and psychiatric disorders

Oxytocin (OT) is involved in the regulation of physiological processes and emotional states, with increasing evidence for its beneficial actions being mediated by the autonomic and immune systems. Growing evidence suggests that OT plays a role in the pathophysiology of different psychiatric disorders. Given the limited information in humans the aim of this study was to retrospectively explore plasma OT levels in psychiatric patients, particularly focusing on sex-related differences, as compared with healthy controls. The patients studied here were divided into three groups diagnosed with obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD) or major depressive disorder (MDD). Plasma OT levels were significantly different between healthy men and women, with the latter showing higher values, while none of the three psychiatric groups showed sex-related differences in the parameters measured here. The intergroup analyses showed that the OT levels were significantly higher in OCD, lower in PTSD and even more reduced in MDD patients than in healthy subjects. These differences were also confirmed when gender was considered, with the exception of PTSD men, in whom OT levels were similar to those of healthy men. The present results indicated that OT levels were higher amongst healthy women than men, while a sex difference was less apparent or reversed in psychiatric patients. Reductions in sex differences in psychopathologies may be related to differential vulnerabilities in processes associated with basic adaptive and social functions.

Functional neurologic disorders in an adult with propionic acidemia: a case report

BACKGROUND

Inborn errors of metabolism are often characterized by various psychiatric syndromes. Previous studies tend to classify psychiatric manifestations into clinical entities. Among inborn errors of metabolism, propionic acidemia (PA) is a rare inherited organic aciduria that leads to neurologic disabilities. Several studies in children with PA demonstrated that psychiatric disorders are associated to neurological symptoms. To our knowledge, no psychopathological description in adult with propionic acidemia is available.

CASE PRESENTATION

We aimed to compare the case of a 53-year-old woman with PA, to the previous psychiatric descriptions in children with PA and in adults with other inborn errors of metabolism. Our patient presented a large variety of signs: functional neurologic disorders, borderline personality traits (emotional dyregulation, dissociative and alexithymic trends, obsessive-compulsive disorders), occurring in a context of neurodevelopmental disorder.

CONCLUSION

Clinical and paraclinical examinations are in favor of a mild mental retardation since childhood and disorders of behavior and personality without any definite psychiatric syndrome, as already described in other metabolic diseases (group 3). Nonetheless, further studies are needed to clarify the psychiatric alterations within adult patients with PA.

Diffusion-Weighted MRI Findings of Caudate Nucleus and Putamen in Patients With Obsessive-Compulsive Disorder

Objective The purpose of this study was to establish the diffusion-weighted magnetic resonance imaging (DW-MRI) findings of the caudate nucleus and putamen in patients with obsessive-compulsive disorder (OCD) and to obtain new information on the etiopathogenesis of OCD, which is still unclear. Methods The study comprised 20 patients with OCDs and 20 healthy volunteers. In these cases, DW-MRI and diffusion-weighted echo-planar images (DW-EPI) at b600 and b1000 gradient values were taken and the measurements were made using the apparent diffusion coefficient (ADC) maps of each group at b600 and b1000 values from the caudate nucleus and putamen. Results When the DW-MRI examination in patients with OCD was compared with the control group, the mean ADC values in the caudate nucleus and putamen were not found to have statistically significantly changed. In addition, there were no significant differences regarding the right and left caudate nuclei and putamen ADC values at the b600 and b1000 in the patients with OCD or the control group. Conclusion There are still many unknowns about the neurobiology of OCD. When the DW-MRI examination of the patients with OCD was compared with the control group in our study, no significant difference was found between the ADC values of the caudate nucleus and putamen. Further studies are required for this present study on DW-MRI in patients with OCD to be meaningful.

A Developmental Psychopathology Perspective of Obsessive-Compulsive Disorder

Objective:

This integrative review explores Obsessive-Compulsive Disorder (OCD) from the perspective of developmental psychopathology, in terms of its multifaceted etiology and course.

Background:

Individuals affected by OCD experience intrusive and undesired thoughts accompanied by behaviors used to mitigate the unwanted images. Accordingly, there are several sub-types and personality dispositions reflective of the overall continuum of OCD, spanning normality and psychopathology. The etiology is complex, with generalized psychological and biological vulnerabilities, as well as contributors from life stress. Moreover, OCD is a disorder with a highly comorbid and overlapping presence; therefore, difficulties may arise when differentiating between OCD and other problems.

Conclusion:

Treatment non-responsiveness is a pervasive trend in persons afflicted with OCD, but the most effective approach likely involves a stepped-care model incorporating cognitive-behavioral psychotherapy and psychotropic medications. Other considerations will also be discussed.

Pre-specified Anxiety Predicts Future Decision-Making Performances Under Different Temporally Constrained Conditions

In real-life circumstances, people occasionally require making forced decisions when encountering unpredictable events and situations that yield socially and privately unfavorable consequences. In order to prevent future negative consequences, it is beneficial to successfully predict future decision-making behaviors based on various types of information, including behavioral traits and/or psychological states. For this prospective purpose, the present study used the Iowa Gambling Task, which simulates multiple aspects of real-life decision-making processes, such as choice preference, selection and evaluation of output feedback, and investigated how anxiety profiles predict decision-making performances under conditions with different temporal pressures on task execution. To conduct a temporally causal analysis, we assessed the trait and state anxiety profiles of 33 young participants prior to the task and analyzed their subsequent decision-making performances. We separated two disadvantageous card decks with high rewards and losses into high- and middle-risk decks, and calculated local performance indexes for decision-making immediately after salient penalty events for the high-risk deck in addition to traditional global performance indexes concerning overall trial outcomes such as final winnings and net scores. For global decision-making, higher trait anxiety predicted more risky choices solely in the self-paced condition without temporal pressure. For local decision-making, state anxiety predicted risk-taking performances differently in the self- and forced-paced conditions. In the self-paced condition, higher state anxiety predicted higher risk-avoidance. In the forced-paced condition, higher state anxiety predicted more frequent choices of the middle-risk deck. These findings suggest not only that pre-specified anxiety profiles can effectively predict future decision-making behaviors under different temporal pressures, but also newly indicate that behavioral mechanisms for moderate risk-taking under an emergent condition should be focused on to effectively prevent future unfavorable consequences when actually encountering negative events.

Neurological soft signs, dissociation and alexithymia in patients with obsessive-compulsive disorder (OCD) and healthy subjects

A body of evidence has supported that patients with obsessive-compulsive disorder (OCD) have increased rates of various neurological soft signs (NSS) compared to controls. Various lines of research has documented robust relationships between OCD and dissociative symptomatology. The study aimed to examine the associations between obsessive-compulsive symptoms, dissociative experiences alexithymia, and NSS. The study included thirty OCD patients and thirty healthy controls, matched for age, marital status, education, and income. The Neurological Evaluation Scale (NES), Padua Inventory-Revised (PI-R), Dissociative Experiences Scale (DES) and Toronto Alexithymia Scale (TAS-20) were administered. In comparison to healthy controls, patients with OCD had difficulty sequencing for complex motor acts and greater absorption/ imaginative involvement. Using latent class analysis, the study sample was classified into two homogenous subsets as mild NSS (n = 45) and severe NSS (n = 15). Majority of the participants who were grouped into severe NSS latent class were OCD patient (n = 14, 93.3%). Furthermore, those with severe NSS reported greater levels of alexithymia and more severe obsessive-compulsive symptoms, particularly precision. We concluded that relationships between OCD severity and NSS appear to be of crucial importance. Our data along with accumulated evidence suggest that OCD associated with pronounced NSS may represent a specific subtype of the disorder.

Animal models of drug addiction: Where do we go from here?

Compulsion and impulsivity are both primary features of drug addiction. Based on decades of animal research, we have a detailed understanding of the factors (both environmental and physiological) that influence compulsive drug use, but still know relatively little about the impulsive aspects of drug addiction. This review outlines our current knowledge of the relationship between impulsivity and drug addiction, focusing on cognitive and motor impulsivity, which are particularly relevant to this disorder. Topics to be discussed include the influence of chronic drug administration on impulsivity, the mechanisms that may explain drug-induced impulsivity, and the role of individual differences in the development of impulsive drug use. In addition, the manner in which contemporary theories of drug addiction conceptualize the relationship between impulsivity and compulsion is examined. Most importantly, this review emphasizes a critical role for animal research in understanding the role of impulsivity in the development and maintenance of drug addiction.

Neuroimaging Studies in Obsessive Compulsive Disorder: A Narrative Review

Obsessive compulsive disorder (OCD) is a relatively common psychiatric illness with a lifetime prevalence of 2-3% in general population. The pathophysiology of OCD is not yet fully understood, however over the last few decades, evidence for abnormalities of cortico-striatal-thalamic-cortico (CSTC) circuitry in etiopathogenesis of OCD has accumulated. Recent brain imaging techniques have been particularly convincing in suggesting that CSTC circuits are responsible for mediation of OCD symptoms. Neuroimaging studies, especially more recent studies using functional neuroimaging methods have looked for possible changes seen in the brain of patients with OCD, the specificity of the findings (as compared to other psychiatric illnesses) and the effects of treatment (pharmacotherapy/psychotherapy) on such changes were observed. This narrative review discusses the neuroimaging findings seen in patients with OCD with a special focus on relatively more recent neuroimaging modalities such as magnetic resonance spectroscopy and magnetoencephalography.

Experimental evidence for involvement of nitric oxide in low frequency magnetic field induced obsessive compulsive disorder-like behavior

It is well documented that extremely low frequency magnetic field (ELF MF) produced effects on the function of nervous system in humans and laboratory animals. Dopaminergic and serotonergic pathways have been implicated in obsessive compulsive disorder (OCD). Recently involvement of nitric oxide (NO) in OCD-like behavior is suggested. Hence, the present study was carried out to understand the involvement of dopamine, serotonin and NO in ELF MF induced OCD-like behavior. Swiss albino mice were exposed to ELF MF (50 Hz, 10G) for 8 h/day for 7, 30, 60, 90 and 120 days by subjecting them to Helmholtz coils. OCD-like behavior was assessed in terms of marble burying behavior (MBB) test. Results revealed that ELF MF induced time dependant MBB, on 7th, 30th, 60th, 90th, and 120th exposure day. Further, levels of dopamine, serotonin and NO after 120 days of ELF MF exposure were determined in the regions of the brain. The neurohumoral studies revealed that exposure to ELF MF increased NO levels in cortex, hippocampus and hypothalamus, and levels of dopamine and serotonin remain unaffected. As OCD-like behavior after ELF MF exposure was associated with higher levels of NO with no significant change in serotonin and dopamine. The effect of such exposure was studied in groups concurrently treated with NO modulators, NO precursor, L-ARG (400 mg/kg) or NOS inhibitor, L-NAME (15.0mg/kg) or 7-NI (10.0 mg/kg). These treatments revealed that NO precursor exacerbated and NOS inhibitors attenuated ELF MF induced OCD-like behavior with corresponding changes in the levels of NO.

Socioemotional deficits associated with obsessive-compulsive symptomatology

Increasing emphasis has been placed on the role of socioemotional functioning in models of obsessive-compulsive disorder (OCD). The present study investigated whether OCD symptoms were associated with capacity for theory of mind (ToM) and basic affect recognition. Non-clinical volunteers (N=204) completed self report measures of OCD and general psychopathology, in addition to behavioral measures of ToM and affect recognition. The results indicated that higher OCD symptoms were associated with reduced ToM, as well as reduced accuracy decoding the specific emotion of disgust. Importantly, these relationships could not be attributed to other, more general features of psychopathology. The findings of the current study therefore further our understanding of how the processing and interpretation of social and emotional information is affected in the context of OCD symptomatology, and are discussed in relation to neuropsychological models of OCD.

Transcendence, guilt, and self-control

Transcendence, defined as the capacity to perceive the immediate stimulus environment in relation to long-range or abstract concerns, is a key aspect of self-control, and indeed self-regulation often breaks down because attention becomes focused exclusively on the immediate stimuli (i.e., transcendence fails). Factors that restrict attention to the here and now will weaken self-control, whereas factors that promote transcendence will enhance it. Guilt may be one example of the latter.

The future is uncertain: Eat dessert first

There may be evolutionary as well as economic reasons why organisms generally act impulsively. I discuss this possibility and suggest some follow-up experiments that may clarify the exciting empirical and theoretical contributions made by the experiments discussed in the target article.

The behavior of self-control

Rachlin's view of self-control as a sequence or chain of behaviors is contrasted with traditional behavioral analyses of self-control which emphasize a simplistic interpretation of the hyperbolic function relating small-sooner (SS) and larger-later (LL) reinforcers to specific behaviors. The validity of Rachlin's teleological analysis is examined in relation to the acquisition and steady-state performance of self-control behaviors. Central to an analysis of self-control is the functional difference between behavior under the control of SS and LL reinforcers, because SS-reinforced behavior is more complex due to temporal parameters.

The extended psychological present

Portraying psychological process as extended over time in multiply overlapping scales is a conceptual advance that can be understood as analogous to our understanding of spatial relationships. There may be a residual contradiction, however, when Rachlin invokes “cost” in ways that seem to imply earlier conceptions. The roles of superimposed or conditionally related stimuli also remain to be addressed.

Conceptualizing self-control

A pair of arguments suggests that self-control is not properly conceptualized on the pattern/act/preference model Rachlin proposes. The first concerns the irrational following of personal rules. The second concerns scenarios in which behavioral patterns an agent deems good come into conflict.

Patterns, acts, and self-control: Rachlin's theory

Regarding Rachlin's behavioral act/pattern theory of self-control, it is argued that some cases of self-control involve pattern/ pattern conflicts rather than merely act/pattern conflicts and that – if all cases of self-control are to be accounted for – some patterns must be viewed as internal representational states of mind (plans) rather than merely as patterns of actual overt behavior.

Choice between long- and short-term interests: Beyond self-control

In the real world, there are choices between large, delayed, punctate rewards and small, more immediate rewards as well as choices between patterns and acts. A common element in these situations is the choice between long- and short-term interests. Key issues for future research appear to be how acts are restructured into larger patterns of behavior, and whether, as Rachlin implies, pattern perception is the cause of pattern generation.

Self-control: Beyond commitment

Self-control, so important in the theory and practice of psychology, has usually been understood introspectively. This target article adopts a behavioral view of the self (as an abstract class of behavioral actions) and of self-control (as an abstract behavioral pattern dominating a particular act) according to which the development of self-control is a molar/molecular conflict in the development of behavioral patterns. This subsumes the more typical view of self-control as a now/later conflict in which an act of self-control is a choice of a larger but later reinforcer over a smaller but sooner reinforcer. If at some future time the smaller-sooner reinforcer will be more valuable than the larger-later reinforcer, self-control may be achieved through a commitment to the largerlater reinforcer prior to that point. According to some, there is a progressive internalization of commitment in the development of self-control. This presents theoretical and empirical problems. In two experiments – one with pigeons choosing between smallersooner and larger-later reinforcers, the other with adult humans choosing between short-term particular and long-term abstract reinforcers – temporal patterning of choices increased self-control.

Cognitive disturbances in primary blepharospasm

The common belief that primary dystonia is a purely motor disorder with no anatomical substrate and no other accompanying neurological dysfunction has recently been challenged. In addition, there is increasing evidence that the basal ganglia besides motor control, plays a role in cognitive functioning. However, no systematic cognitive performance evaluation has been carried out in patients with primary blepharospasm (BS), one of the most common forms of adult dystonia. We evaluated a series of 20 patients with primary BS and a group of 17 controls matched by severity of mood symptoms, age, and sex. BS patients performed significantly worse on the Luria sequencing test, Purdue pegboard test, reciprocal coordination, tactile denomination, and reverse visuospatial span and the differences persisted after correction for age, duration of disease, severity of BS, and degree of depression. The Wisconsin card sorting test showed no statistical difference, but BS patients made more errors and more perseverative answers than expected according to population means, whereas the control group performed poorly but within normal parameters. Our findings suggest broad cortical involvement in focal dystonia that is not correlated with the severity or duration of dystonia.

RIGHT BASAL GANGLION HYPOPERFUSION IN OBSESSIVE COMPULSIVE DISORDER PATIENTS DEMONSTRATED BY Tc-99m-HMPAO BRAIN PERFUSION SPECT: A CONTROLLED STUDY

The aim of this study is to demonstrate the regional cerebral blood flows (rCBF) of obsessive-compulsive disorder (OCD) patients compared to controls by using Tc-99m-HMPAO SPECT. Sixteen OCD and seven control subjects were admitted into the study. Yale-Brown Obsessive Compulsive Rating Scale (Y-BOCS), Hamilton Depression Rating Scale (HDRS), and Hamilton Anxiety Rating Scale (HARS) were applied to the patients. The rCBF was found to be decreased in right basal ganglion in OCD patients. The right basal ganglion rCBF was negatively correlated with Y-BOCS total and compulsion scores. The left thalamus rCBF was negatively correlated with Y-BOCS obsession score. Right and left cingulate rCBF were negatively correlated with HDRS score. The results indicating hypoperfusion in right basal ganglion in OCD patients support previous findings about dysfunction of frontal-subcortical circuits in this disorder.

Obsessive-Compulsive Hoarding: A Cognitive-Behavioural Approach

Obsessive-compulsive hoarding can be viewed within personality, neuroethological and cognitive-behavioural frameworks. Three cases of obsessive-compulsive hoarding are described in detail. All cases had some insight (albeit fluctuating) into their problem and were seeking treatment. There was evidence of abnormal risk assessment, fear of criticism, excessive guilt, overconscientiousness and inflated responsibility. Depression, emotional or material deprivation and significant loss during childhood and adolescence were experienced by all cases. The cases are considered to be consistent with a cognitive-behavioural model of obsessive-compulsive disorder emphasizing the importance of learning and cognition. Implications for treatment are discussed.

Memory for Actions in Obsessive-Compulsive Disorder

Frequent checkers with obsessive-compulsive disorder (OCD; n=24), high checking controls (n=24) and low checking controls (n=48) were instructed to learn action phrases such as “to open the book” by performing the action themselves with imaginary objects (motor encoding), by imagining how one performs the action oneself (motor-imaginal encoding), by imagining seeing somebody else performing the action (visual-imaginal encoding) and by subvocal rehearsal. Compared to low checking controls, OCD checkers showed poorer free recall of motorically encoded actions and poorer reality monitoring, i.e. they confused motor and motor-imaginal encoding more frequently. The results are consistent with a specific motor memory deficit in OCD checkers. Moreover, memory performance of OCD checkers differed from that of high checking controls.

Ritual Behavior in Obsessive and Normal Individuals

Ritualized behavior is characteristic of obsessive-compulsive disorder (OCD), but it is also observed in other, nonclinical contexts such as children's routines and cultural ceremonies. Such behaviors are best understood with reference to a set of human vigilance–precaution systems in charge of monitoring potential danger and motivating the organism toward appropriate precautions. Ritualized behavior focuses attention on low-level representations of actions, probably leading to some measure of intrusion suppression. Cultural rituals too may be understood in this framework.

A study of neuropsychological deficit in children with obsessive-compulsive disorder

This study was conducted to examine the neuropsychological deficits in children with obsessive compulsive disorder (OCD). Furthermore, the focus of present study was to explore whether OCD children show the same executive dysfunction as adult OCD patients. The participants consisted of 106 children between the ages of 6 and 16 years who visited the department of child-adolescent psychiatry, Seoul National University Children's Hospital (17 OCD, 25 ADHD, 21 tic disorder, 20 depressive disorder, and 23 healthy children). The OCD children showed higher verbal ability compared to other psychiatric groups, but performed the worst on WISC-R subtests assessing perceptual organization ability under time pressure. The OCD children did not show any significant deficits in verbal intellectual function, memory, attention and concentration abilities. However, similar to the ADHD children, the OCD children had significantly more errors and completed fewer categories on the WCST compared to the healthy group. Through neuropsychological tests, the OCD children showed cognitive strength and weakness similar to those of OCD adults that were reported in previous research. Specifically, they had executive function deficits in mental set shifting, supporting the frontal-striatal dysfunction hypothesis of OCD in children as well as in adults.

Subtyping obsessive-compulsive disorder: clinical and immunological findings in child and adult onset

It has been suggested that certain kinds of childhood OCD with specific clinical, biological and immunological characteristics may form a subgroup of OCD. We study the presence of these characteristics in child onset OCD and propose that the disorder be considered as a subtype of adult OCD. Forty adult patients with OCD were divided in two groups according to time of disease onset: 18 early onset and 21 late. Both sets were compared with a control group of 14 psychiatric patients. Child onset OCD was associated with higher mean ASLO titers, higher frequencies of history of tic disorders and tonsillitis in childhood and compulsive symptoms. No differences were found in D8/17 antibody titers or in other autoimmune parameters. The findings suggest that child onset OCD can be considered as a subgroup of adult OCD, although more specific biological markers are needed to identify it.

Opioids and alcoholism

Although far from conclusive, evidence implicating the endogenous opioid system in the development and maintenance of alcoholism is growing. Currently available data suggest that ethanol increases opioid neurotransmission and that this activation is part of the mechanism responsible for its reinforcing effects. Findings from preclinical research indicate that ethanol consumption and ethanol-induced dopamine (DA) release are both reduced by opioid antagonists. Individual differences in endogenous opioid activity have been linked to inherited risks for alcoholism in studies comparing ethanol-preferring and nonpreferring rats, as well as in studies using targeted gene mutation (knockout) strategies. To a large extent, findings from human studies have paralleled those from the preclinical work. Persons who differ in family history of alcoholism have been shown to also differ in basal beta-endorphin activity, beta-endorphin response to alcohol, and subjective and HPA axis hormonal response to opioid antagonists. Findings from clinical trials indicate that opioid antagonists may reduce ethanol consumption in alcoholics, particularly in persons who have resumed drinking. Nevertheless, many questions remain unanswered about the use of opioid antagonists in alcoholism treatment and about the exact role of the opioid system in ethanol preference and reward. The progression of knowledge in this field suggests that many of these questions are imminently answerable, as our ability to characterize relationships between opioid activity and human behavior continues to develop. This paper summarizes both the progress that has been made and the gaps that remain in our understanding of the interactions between the endogenous opioid system and risk for alcoholism.

Neuropsychological performance in obsessive-compulsive disorder: a critical review

There is growing evidence for neuropsychological dysfunction in obsessive-compulsive disorder (OCD) related to an underlying frontal lobe and/or basal ganglia dysfunction. The following paper is a systematical review of the existing literature on cognitive impairment in OCD patients. Fifty studies were surveyed with regard to methodological aspects and cognitive impairments found in OCD patients. In addition, the impact of confounding variables such as psychotropic medication, co-morbidity or severity of symptoms on neuropsychological functioning as well as effects of treatment are discussed. OCD is often related to memory dysfunction that seems to be associated with impaired organization of information at the stage of encoding. Several other executive functions are also commonly disturbed, though results are inconsistent. The results of our study suggest that some cognitive deficits seem to be common in OCD, but future studies should focus more on possible confounding variables such as co-morbidity or psychotropic medication.

Pathophysiology of obsessive–compulsive disorder

Obsessive-compulsive disorder (OCD) is characterized by repetitive intrusive thoughts and compulsive time-consuming behaviors classified into three to five distinct symptom dimensions including: (1) aggressive/somatic obsessions with checking compulsions; (2) contamination concerns with washing compulsions; (3) symmetry obsessions with counting/ordering compulsions; (4) hoarding obsessions with collecting compulsions; and (5) sexual/religious concerns. Phenomenologically, OCD could be thought of as the irruption of internal signals centered on the erroneous perception that "something is wrong" in a specific situation. This generates severe anxiety, leading to recurrent behaviors aimed at reducing the emotional tension. In this paper, we examine how the abnormalities in brain activity reported in OCD can be interpreted in the light of physiology after consideration of various approaches (phenomenology, neuropsychology, neuroimmunology and neuroimagery) that contribute to proposing the central role of several cortical and subcortical regions, especially the orbitofrontal cortex (OFC), the anterior cingulate cortex (ACC), the dorsolateral prefrontal cortex (DLPC), the head of the caudate nucleus and the thalamus. The OFC is involved in the significance attributed to the consequences of action, thereby subserving decision-making, whereas the ACC is particularly activated in situations in which there are conflicting options and a high likelihood of making an error. The DLPC plays a critical part in the cognitive processing of relevant information. This cortical information is then integrated by the caudate nucleus, which controls behavioral programs. A dysfunction of these networks at one or several stages will result in the emergence and maintenance of repetitive thoughts and characteristic OCD behavior.

Facial expression recognition in people with medicated and unmedicated Parkinson's disease

Recognition of facial expressions of emotion was investigated in people with medicated and unmedicated Parkinson's disease (PD) and matched controls (unmedicated PD, n=16; medicated PD, n=20; controls, n=40). Participants in the medicated group showed some visual impairment (impaired contrast sensitivity) and performed less well on perception of unfamiliar face identity, but did not show significant deficits in the perception of sex, gaze direction, or familiar identity from the face. For both Parkinson's disease groups, there was evidence of impaired recognition of facial expressions in comparison to controls. These deficits were more consistently noted in the unmedicated group, who were also found to perform worse than the medicated group at recognising disgust from prototypical facial expressions, and at recognising anger and disgust in computer-manipulated images. Although both Parkinson's disease groups showed impairments of facial expression recognition, the consistently worse recognition of disgust in the unmedicated group is consistent with the hypothesis from previous studies that brain regions modulated by dopaminergic neurons are involved in the recognition of disgust.

Neuropsychological performance and regional cerebral blood flow in obsessive-compulsive disorder

Convergent findings from neuropsychological and neuroimaging studies have suggested that neural dysfunction in frontal-subcortical circuits may play a central role in the pathophysiology of obsessive-compulsive disorder (OCD). To further examine the relationship between these two sets of findings we investigated both neuropsychological functions and regional cerebral blood flow (rCBF) in a combined study. Fourteen unmedicated patients fulfilling DSM-IV criteria for OCD and 14 healthy controls matched for age, gender, handedness, and education were assessed on neuropsychological tests that included Trail Making Test (TMT), Rey Complex Figure Test (RCF) (copy and 5-min recall), Verbal Fluency Test (VFT), and Wisconsin Card Sorting Test (WCST). rCBF was studied with 99 mTc-hexamethyl-propyleneamine-oxime (HMPAO) single photon emission computed tomography (SPECT). Patients performed more poorly than controls (P<.05) on RCF (copy), VFT, and WCST (perseverative errors). Spearman's correlations indicated that severity of OCD correlated inversely with performance on the RCF (copy and recall scores) and positively with rCBF in the right thalamus. Positive correlations were observed between nonperseverative errors (WCST) and rCBF in frontal areas and anterior cingulate. Perseverative errors (WCST) correlated negatively with rCBF in the right thalamus. These findings are consistent with most previously published studies and suggest neural dysfunctions in the frontal-subcortical circuits probably more pronounced in the right hemisphere. They also extend the existing research, showing associations between deficits in cortical-subcortical circuitry and performance on neuropsychological tests of controlled attention and visuospatial functions.

Neuropsychological performance in medicated vs. unmedicated patients with obsessive-compulsive disorder

To date, there have been no formal investigations of neuropsychological performance in patients with obsessive-compulsive disorder (OCD) taking psychotropic medications. The purpose of this study was to determine whether medicated and unmedicated patients with OCD demonstrate differences in neuropsychological functioning. Fifty-two patients with a primary DSM-IV diagnosis of OCD participated in the study; 28 were taking serotonin reuptake inhibitors (SRIs), and 24 were treatment-naïve (n=8) or had finished a washout period prior to their inclusion in other studies (n=16). The groups were well matched with regard to demographic and clinical variables, including symptom severity. Each group was administered a comprehensive neuropsychological battery to assess general intelligence, attention, verbal and non-verbal working memory, declarative and procedural learning, visuo-constructive skills, and executive functions. SRI-medicated did not differ from SRI-free patients on any neuropsychological measure. Benzodiazepines seemed to improve the patients' functioning on a semantic verbal fluency test. In addition, there were significant interactions between SRIs and benzodiazepines on the perseverative errors of the Wisconsin Card Sorting Test and on reaction times. SRI-medicated patients with OCD are able to perform on cognitive functioning tests at a comparable level with that of SRI-free patients, and these results have positive implications for OCD patients who respond to SRIs. The interactions between SRIs and benzodiazepines and their effect on cognition in OCD are likely to be complex and deserve further study.

Kinematic analysis of handwriting movements in patients with obsessive-compulsive disorder

OBJECTIVES

Basal ganglia dysfunction is supposed to play a part in the pathophysiology of obsessive-compulsive disorder (OCD). A new computer aided technique for the analysis of hand movements, allowing the detection of subtle motor performance abnormalities, was applied in this study of patients with OCD and healthy controls.

METHODS

Using a digitising graphic tablet, hand motor performance was studied in 22 unmedicated patients with OCD and compared with 22 healthy controls. All subjects drew superimposed concentric circles with both the right and the left hand, in addition to writing a given sentence, their personal signature, and letter sequences in four different sizes. Kinematic parameters were calculated to quantify hand motion.

RESULTS

Patients with OCD had significant impairments of handwriting performance, reflected by lower peak velocity (sentence t=3.6; p=0.001; signature t=2.8; p=0.01) and micrographia (sentence t=3.4; p=0.002; signature t=2.5; p=0.02), compared with controls and shortened acceleration phases per stroke (sentence t=2.4; p=0.02; signature t=4.1; p=0.000). By contrast, in repetitive drawing, patients with OCD had higher peak velocity than healthy controls (group x task interaction p<0.01). There were no significant differences in left and right hand performance between groups. Patients with early versus late age of onset differed in handwriting parameters, such as handwriting consistency. Greater severity of obsessions and compulsions correlated with increasingly poor handwriting performance in patients with OCD.

CONCLUSIONS

A subtle motor dysfunction in OCD can be detected with a digitising tablet. The findings show handwriting impairments in patients with OCD, in line with the assumption that basal ganglia dysfunction is part of OCD pathophysiology. Repetitive motor pattern performance was not impaired, but rather tended to be even better in patients with OCD than in controls. The findings also support the concept that patients with OCD with early versus late age of onset differ in pathophysiological mechanisms and basal ganglia dysfunction.

On the role of prefrontal cortex glutamate for the antithetical phenomenology of obsessive compulsive disorder and attention deficit hyperactivity disorder

1. The objective of the present study was to compare the phenomenology and pathophysiology of obsessive compulsive disorder (OCD) and attention deficit hyperactivity disorder/deficits in attention, motor control and perception (ADHD/DAMP). 2. Through detailed studies of the literature on OCD and ADHD/DAMP, the phenomenology of these two conditions is compared, and possible underlying pathophysiological mechanisms involving interactions between glutamate, dopamine, serotonin and acetylcholine are discussed, with emphasis on OCD. The present paper also discusses possible mechanisms of action for current pharmacological treatments of OCD and ADHD, as well as possible future treatment strategies for these disorders. 3. OCD and ADHD/DAMP are common neuropsychiatric conditions which in many regards appear to be each other's antipodes with respect to clinical manifestations, associated personality traits and brain biochemistry, notably prefrontal cortical glutamate activity. Future pharmacological treatments of these disorders may involve manipulations with glutamate, dopamine D , serotonin 2A and nicotine receptors. 4. It appears that OCD is a hyperglutamatergic and ADHD a hypoglutamatergic condition, with prefrontal brain regions being especially affected.

Zur Bedeutung von Gedächtnisprozessen für das Verständnis von Kontrollzwängen

Zusammenfassung.Theoretischer Hintergrund und Fragestellung: Menschen mit Kontrollzwängen berichten häufig, daß Gedächtnisbeeinträchtigungen zu ihrer Symptomatik beitragen. Die Arbeit gibt einen Überblick über neuere Studien zum verbalen, visuellen und Handlungsgedächtnis bei Menschen mit Zwangsstörungen und evaluiert sie im Hinblick auf ihre Bedeutung für das Verständnis von Kontrollzwängen. Methode: Es handelt sich um eine Übersichtsarbeit mit detaillierter Analyse und kritischer Diskussion dieser Studien. Ergebnisse: Insgesamt ist von wahrscheinlich intakten verbalen und relativ konsistent beeinträchtigten visuellen Gedächtnisleistungen auszugehen. Die Befundlage zum Handlungsgedächtnis (Free Recall, Rekognition, Reality Monitor-ing, Vertrauen ins eigene Gedächtnisurteil) ist uneinheitlich. Schlußfolgerungen: Die Wichtigkeit ökologischer Validität durch “Phänomennähe“ bei der Konstruktion experimenteller Aufgaben und theoretischer Ansätze zum besseren Verständnis der Unzufriedenheit von ZwangspatientInnen mit ihrem Erinnerungserleben wird hervorgehoben.

A neural network of obsessive- compulsive disorder: modelling cognitive disinhibition and neurotransmitter dysfunction

While significant advances have been made in documenting both neurotransmitter and neuropsychological dysfunction in obsessive-compulsive disorder (OCD), there remains a need for theoretical models to account for their relationship. A neural network model of OCD was developed to provide a rigorous simulation of the relationship between the cognitive disinhibition and serotonin/dopamine dysfunction that characterize this disorder. An architecture-specific recurrent neural network of the Elman type was able to model the cognitive disinhibition that is apparent when OCD patients are compared with other anxiety disorder patients on a modified Stroop (Temporal Stroop) test, with OCD patients showing reduced negative priming (shorter reaction times to previously ignored stimuli). Lesions to either the color gain parameter (reflective of serotonergic dysfunction) or to the context gain parameter (reflective of dopaminergic dysfunction) resulted in decreased semantic negative priming. Neural network modelling provides a surprisingly coherent perspective of the psychobiology of OCD, simulating both reduced cognitive disinhibition as well as neurotransmitter dysfunction.

Self-help and guided self-help treatments for bulimia nervosa and binge eating disorder

This article reviews the use of self-help and guided self-help treatments for bulimia nervosa (BN) and binge eating disorder (BED). Available data suggest that self-help and guided self-help treatments based on empirically-supported cognitive behavioral therapies (CBT) have efficacy for binge eating problems. Emerging findings from initial studies suggest that the magnitude of the differences in outcomes between certain guided-self-help CBT programs and therapist-led CBT may not be substantial, although further research is clearly indicated. Initial data suggest that self-help and guided self-help CBT programs may not only demonstrate "efficacy" but also "effectiveness"-i.e., utility in "real-world" primary care or community settings. Implications for clinical practice and for future research are discussed.

Proton magnetic resonance spectroscopy of lenticular nuclei in obsessive-compulsive disorder

Magnetic resonance spectroscopy (MRS) is a safe and non-invasive technique for the in vivo study of brain chemistry and metabolism. As such, it is highly applicable to the study of living brain tissue in psychiatric diseases. Several neuropathological and neuroimaging studies have suggested that abnormalities of the basal ganglia nuclei might be implicated in patients with obsessive-compulsive disorder (OCD). In the present study, we performed proton [1H]MRS of the lenticular nuclei in 12 patients with OCD and 12 healthy normal comparison subjects. The peaks of N-acetyl-aspartate (NAA), creatine (Cr), and choline-containing compounds (Cho) were measured. No differences between OCD patients and normal subjects were found in the NAA/Cr, Cho/Cr and NAA/Cho ratios. Our results suggest the normal viability of neuronal cells, as indicated by the quantification of NAA, Cr and Cho in the lenticular nuclei of patients with OCD.

Organizational strategies mediate nonverbal memory impairment in obsessive-compulsive disorder

BACKGROUND

Previous neuropsychological studies of obsessive-compulsive disorder (OCD) have indicated impaired executive functioning and nonverbal memory. The extent to which impaired executive functioning impacts nonverbal memory has not been established. The current study investigated the mediating effects of organizational strategies used when copying a figure on subsequent nonverbal memory for that figure.

METHODS

We examined neuropsychological performance in 20 unmedicated subjects with OCD and 20 matched normal control subjects. Subjects were administered the Rey-Osterrieth Complex Figure Test (RCFT) and neuropsychological tests assessing various aspects of executive function.

RESULTS

OCD subjects differed significantly from healthy control subjects in the organizational strategies used to copy the RCFT figure, and they recalled significantly less information on both immediate and delayed testing. Multiple regression analyses indicated that group differences in immediate percent recall were significantly mediated by copy organizational strategies. Further exploratory analyses indicated that organizational problems in OCD may be related to difficulties shifting mental and/or spatial set.

CONCLUSIONS

Immediate nonverbal memory problems in OCD subjects were mediated by impaired organizational strategies used during the initial copy of the RCFT figure. Thus, the primary deficit was one affecting executive function, which then had a secondary effect on immediate memory. These findings are consistent with current theories proposing frontal-striatal system dysfunction in OCD.

Neuropsychological functioning in a subclinical obsessive-compulsive sample

BACKGROUND

Previous neuropsychological research has suggested that the study of psychometrically defined subclinical samples might be a valid approach to understand the underlying pathophysiology of obsessive-compulsive disorder (OCD). This approach has the potential benefit of overcoming some of the methodological problems linked to the use of clinical samples.

METHODS

A group of subclinical obsessive-compulsive (OC) subjects (n = 35), selected on the basis of their scores on the Padua Inventory, and a control group were assessed on executive functioning tasks and other neuropsychological tests which have been demonstrated to be impaired in clinical OCD patients and/or in those with several basal ganglia disorders.

RESULTS

Subclinical OC subjects needed significantly more moves than controls to reach the solution criteria on the Tower of Hanoi puzzle, and performance on this test was positively correlated with total score and the Checking factor of the Padua Inventory. There were no between-group differences on the other frontal lobe tests.

CONCLUSIONS

The results suggest that deficits in manipulating spatial information might be basic in OCD, and are congruent with the involvement of the frontostriatal circuits in the disorder.

PANDAS: the search for environmental triggers of pediatric neuropsychiatric disorders. Lessons from rheumatic fever

Pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection (PANDAS) is a relatively new diagnostic construct applied to children or adolescents who develop, and have repeated exacerbations of, tic disorders and/or obsessive-compulsive disorder following group A beta-hemolytic streptococcal infections. The proposed pathophysiology is that the group A beta-hemolytic streptococcal bacteria trigger antibodies that cross-react with the basal ganglia of genetically susceptible hosts leading to obsessive-compulsive disorder and/or tics. This is similar to the etiologic mechanisms proposed for Sydenham's chorea, in which group A beta-hemolytic streptococcal antibodies cross-react with the basal ganglia and result in abnormal behavior and involuntary movements. When first proposed, there was much controversy about the idea that streptococcal infections were etiologically related to rheumatic fever. In a like manner, discussion has arisen about the concept of infection-triggered obsessive-compulsive disorder and tic disorders. We review the historical background to these controversies, give an update on the findings provided by research on PANDAS, and address areas of future study.