Obsessive-compulsive Related Disorders Research Articles

Saccadic eye movements in body dysmorphic disorder

Body dysmorphic disorder (BDD) is characterised by a preoccupation with perceived flaws in appearance, which significantly disrupts functioning and causes distress. The difference in self-perception characteristic of BDD has been related to a bias in visual processing across a variety of stimuli and tasks. However, it is unknown how BDD participants perform on basic saccade tasks using eye tracking. Eighteen BDD and 21 healthy control participants completed a battery of saccadic eye movement tasks (fixation, prosaccade, anti-saccade, and memory guided). No significant differences were noted between the groups regarding behavioural performance or patterns of eye movements; however, there was a trend for BDD participants to make increased anticipatory errors on the prosaccade task. Overall, BDD participants demonstrated largely intact saccadic eye movement characteristics which may differentiate BDD from other obsessive-compulsive related disorders, although future research using larger samples is required. It is consequently argued that abnormalities in visual processing apparent among people with BDD may reflect abnormalities in higher-order visual systems.

Trichotillomania is more related to Tourette disorder than to obsessive-compulsive disorder.

Objective:Trichotillomania (TTM) is characterized by the pulling out of one’s hair. TTM was classified as an impulse control disorder in DSM-IV, but is now classified in the obsessive-compulsive related disorders section of DSM-5. Classification for TTM remains an open question, especially considering its impact on treatment of the disorder. In this review, we questioned the relation of TTM to tic disorder and obsessive-compulsive disorder (OCD).Method:We reviewed relevant MEDLINE-indexed articles on clinical, neuropsychological, neurobiological, and therapeutic aspects of trichotillomania, OCD, and tic disorders.Results:Our review found a closer relationship between TTM and tic disorder from neurobiological (especially imaging) and therapeutic standpoints.Conclusion:We sought to challenge the DSM-5 classification of TTM and to compare TTM with both OCD and tic disorder. Some discrepancies between TTM and tic disorders notwithstanding, several arguments are in favor of a closer relationship between these two disorders than between TTM and OCD, especially when considering implications for therapy. This consideration is essential for patients.

XIX world congress of psychiatry – an important stage in the development of general medical care for people suffering from mental diseases

The article provides information about the XIX World Congress of Psychiatry (August 21-24, 2019, Lisbon, Portugal). The issues of implementing the new ICD-11 diagnostic principles are considered; the main results of changes and modifications in schizophrenic disorders, mood disorders and new diagnostic categories in the new concept of “obsessive-compulsive disorders (OCD) and obsessive-compulsive related disorders” are presented.The clinical utility of ICD-11 consists in the ability to use the diagnostic criteria more accurately than before. The talks of the keynote congress speakers are highlighted, the bottom line in the speeches of experts from many countries is finding effective ways of improving the mental health of a person.

Clinical Practice Guidelines for Cognitive-Behavioral Therapies in Anxiety Disorders and Obsessive-Compulsive and Related Disorders.

CBT is a first-line treatment for most anxiety disorders and obsessive–compulsive-related disorders. It has also been found to be helpful in those with inadequate response to medications. Despite similarity of certain techniques such as exposure and cognitive restructuring, individual disorders have different CBT models, which have been tested and proven to be effective. For some disorders, such as specific phobia and BFRB, primarily behavioral techniques have been found to be helpful. While graded exposure is helpful in the former, habit reversal is recommended for the later. Individual face-to-face therapy has been the most rigorously tested, but group therapy also has been found effective in many conditions. Self-help therapy, such as internet-based therapy, may be helpful, especially when used with intermittent therapist guidance. Exposure using virtual reality, augmentation with mindfulness, and emotional regulation strategies are exciting and emerging strategies for augmenting the effects of CBT. Financial support and sponsorship Nil.

Compulsivity is measurable across distinct psychiatric symptom domains and is associated with familial risk and reward-related attentional capture.

Compulsivity can be seen across various mental health conditions and refers to a tendency toward repetitive habitual acts that are persistent and functionally impairing. Compulsivity involves dysfunctional reward-related circuitry and is thought to be significantly heritable. Despite this, its measurement from a transdiagnostic perspective has received only scant research attention. Here we examine both the psychometric properties of a recently developed compulsivity scale, as well as its relationship with compulsive symptoms, familial risk, and reward-related attentional capture. Two-hundred and sixty individuals participated in the study (mean age=36.0 [SD=10.8] years; 60.0% male) and completed the Cambridge-Chicago Compulsivity Trait Scale (CHI-T), along with measures of psychiatric symptoms and family history thereof. Participants also completed a task designed to measure reward-related attentional capture (n=177). CHI-T total scores had a normal distribution and acceptable Cronbach's alpha (0.84). CHI-T total scores correlated significantly and positively (all p<0.05, Bonferroni corrected) with Problematic Usage of the Internet, disordered gambling, obsessive-compulsive symptoms, alcohol misuse, and disordered eating. The scale was correlated significantly with history of addiction and obsessive-compulsive related disorders in first-degree relatives of participants and greater reward-related attentional capture. These findings suggest that the CHI-T is suitable for use in online studies and constitutes a transdiagnostic marker for a range of compulsive symptoms, their familial loading, and related cognitive markers. Future work should more extensively investigate the scale in normative and clinical cohorts, and the role of value-modulated attentional capture across compulsive disorders.

Inhibition-Related Cortical Hypoconnectivity as a Candidate Vulnerability Marker for Obsessive-Compulsive Disorder

BackgroundObsessive-compulsive disorder (OCD) is a prevalent neuropsychiatric condition, with biological models implicating disruption of cortically mediated inhibitory control pathways, ordinarily serving to regulate our environmental responses and habits. The aim of this study was to evaluate inhibition-related cortical dysconnectivity as a novel candidate vulnerability marker of OCD. MethodsIn total, 20 patients with OCD, 18 clinically asymptomatic first-degree relatives of patients with OCD, and 20 control participants took part in a neuroimaging study comprising a functional magnetic resonance imaging stop signal task. Brain activations during the contrasts of interest were cluster thresholded, and a three-dimensional watershed algorithm was used to decompose activation maps into discrete clusters. Functional connections between these key neural nodes were examined using a generalized psychophysiological interaction model. ResultsThe three groups did not differ in terms of age, education level, gender, IQ, or behavioral task parameters. Patients with OCD exhibited hyperactivation of the bilateral occipital cortex during the task versus the other groups. Compared with control participants, patients with OCD and their relatives exhibited significantly reduced connectivity between neural nodes, including frontal cortical, middle occipital cortical, and cerebellar regions, during the stop signal task. ConclusionsThese findings indicate that hypoconnectivity between anterior and posterior cortical regions during inhibitory control represents a candidate vulnerability marker for OCD. Such vulnerability markers, if found to generalize, may be valuable to shed light on etiological processes contributing not only to OCD but also obsessive-compulsive–related disorders more widely.

Body Dysmorphic Disorder in Adolescents

Background and Objectives: Body Dysmorphic Disorder (BDD) is characterized by an abnormal preoccupation with alleged misshapen body parts. There is often poor insight and effort is made to hide the imagined defects, and consultation may be sought seeking unnecessary cosmetic surgery or procedures. It is underdiagnosed and established treatment protocols are lacking. The disease has a chronic and undulating course and is seriously compromises quality of life. Despite the fact that the prime age of onset of BDD is during adolescence relatively little has been written about it during this phase of life. This review aims to comprehensively cover the present understanding of BDD, including clinical features, epidemiology, psychopathology, nomenclature, comorbidity and management. Methods: A literature search was undertaken using suitable key words on Google Scholar, MEDLINE &amp; PsychoINFO up to June 2018 limited to articles in English. Results: he prevalence of BDD is variable in the general and psychiatric population with equal gender distribution. Both sexes are equally affected. It is associated with poor functioning and a chronic course. There is considerable comorbidity and diagnostic overlap between BDD and obsessive-compulsive disorder, major depressive disorder, social anxiety disorder, anorexia nervosa, schizophrenia spectrum disorders and personality disorders. Psychiatric consultation is often late. Selective Serotonin Reuptake Inhibitors (SSRIs) and Cognitive Behavior Therapy (CBT) are currently the first line modalities for treatment. Internet based CBT, Acceptance and commitment therapy, and repetitive Transcranial Magnetic Stimulation (rTMS) are emerging treatment options. Conclusions: BDD is a complex disorder with still lot of uncertainty about its diagnostic placement, treatment approaches, especially for refractory patients, and prognosis. Further study is needed to clarify its prevalence, especially in adolescents; to fully understand its neurobiological aspects, to determine its exact relation to obsessive compulsive related disorders, and to develop better treatment approaches.

A study on the correlates of habit-, reward-, and fear-related motivations in alcohol use disorder.

We assessed self-reported drives for alcohol use and their impact on clinical features of alcohol use disorder (AUD) patients. Our prediction was that, in contrast to "affectively" (reward or fear) driven drinking, "habitual" drinking would be associated with worse clinical features in relation to alcohol use and higher occurrence of associated psychiatric symptoms. Fifty-eight Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) alcohol abuse patients were assessed with a comprehensive battery of reward- and fear-based behavioral tendencies. An 18-item self-report instrument (the Habit, Reward and Fear Scale; HRFS) was employed to quantify affective (fear or reward) and non-affective (habitual) motivations for alcohol use. To characterize clinical and demographic measures associated with habit, reward, and fear, we conducted a partial least squares analysis. Habitual alcohol use was significantly associated with the severity of alcohol dependence reflected across a range of domains and with lower number of detoxifications across multiple settings. In contrast, reward-driven alcohol use was associated with a single domain of alcohol dependence, reward-related behavioral tendencies, and lower number of detoxifications. These results seem to be consistent with a shift from goal-directed to habit-driven alcohol use with severity and progression of addiction, complementing preclinical work and informing biological models of addiction. Both reward-related and habit-driven alcohol use were associated with lower number of detoxifications, perhaps stemming from more benign course for the reward-related and lack of treatment engagement for the habit-related alcohol abuse group. Future work should further explore the role of habit in this and other addictive disorders, and in obsessive-compulsive related disorders.

A systematic review of the utility of electroconvulsive therapy in broadly defined obsessive-compulsive related disorders

Studies on phytoplankton and in particular Harmful Algal Blooms (HABs) species in southern Mediterranean waters are scarce. We performed from April 2008 to June 2009 weekly investigations on microphytoplankton community structure and abundance in two contrasted marine ecosystems located in the western Moroccan Mediterranean coast, M'diq Bay and Oued Laou Estuary. Simultaneously, we measured the main physico-chemical parameters. Globally, the two studied areas showed comparable values of the assessed abiotic environmental factors. Temperature and salinity followed seasonal variation with values ranging from 13.5 °C to 21.4 °C and 31 to 36.8, respectively. Average nutrient values in surface water ranged from 0.7 to 45.76 μM for dissolved inorganic nitrogen, 0.02–2.10 μM for PO4 and 0.23–17.46 μM for SiO4 in the study areas. A total of 92 taxa belonging to 8 taxonomic classes were found. The highest number of microphytoplankton abundance reached 1.2 × 106 cells L−1 with diatoms being the most abundant taxa. Factorial Discriminant Analysis (FDA) and Spearman correlation test showed a significant seasonal discrimination of dominant microphytoplankton species. These micro-organisms were associated with different environmental variables, in particular temperature and salinity. Numerous HABs species were encountered regularly along the year. Although Dinophysis species and Prorocentrum lima were present in both sites, no Lipophilic Shellfish Poisoning was detected for the analyzed bivalve mollusks. Domoic acid (DA), produced by toxic species of Pseudo-nitzschia was found with concentrations up to 18 µg DA g−1 in the smooth clam Callista chione. Data showed that the observed persistent and dramatic Paralytic Shellfish Poisoning (PSP) intoxication of mollusks resulted probably of Gymnodinium catenatum proliferations in both studied areas. Contrary to C. chione, the cockle Achanthocardia tuberculatum showed a permanent and extremely high toxicity level during the 15 months survey with up to 7545 µg Equivalent Saxitoxin kg−1 flesh (ten times higher than the sanitary threshold of 800 µg eqSTX Kg−1flesh). The present work highlights for the first time the dynamic of microphytoplankton including HABs species and their associated toxin accumulation in the commercially exploited shellfish in the southern western Mediterranean waters of Morocco. Furthermore, the acquired data will help us to improve the monitoring of HABs species and related toxins in these coastal marine systems.

A Systematic Review of the Utility of Electroconvulsive Therapy in Broadly Defined Obsessive-Compulsive-Related Disorders.

To assess the efficacy of electroconvulsive therapy (ECT) in DSM-5 obsessive-compulsive-related disorders (OCRDs) and conditions subsumed under an "extended" OCD spectrum, including tic disorders and self-injurious behaviors. A systematic search of the MEDLINE, Web of Science, Scopus, and LILACS databases and other sources was performed between June 6 and July 2, 2017. Search terms included (Autis*) AND (ECT OR electroconvulsive), (Self-injur*) AND (ECT OR electroconvulsive), (Tic* OR Tourette) AND (ECT OR electroconvulsive), (Body Dysmorphic Disorder OR Dysmorphophobi*) AND (ECT OR electroconvulsive), (Hoard*) AND (ECT OR electroconvulsive), (Trichotillomani*) AND (ECT OR electroconvulsive), (Skin Picking OR Excoriation) AND (ECT OR electroconvulsive), (Grooming) AND (ECT OR electroconvulsive), (Kleptomani*) AND (ECT OR electroconvulsive), and (Pyromani*) AND (ECT OR electroconvulsive). No search restrictions (ie, date, language, or document type) were used. Fifty-two records that described the individual responses of OCRDs to ECT (involving 69 patients) were selected. Clinical data and responses of individual cases were recorded. Data from responders were compared to nonresponders. All records were case reports or case series; there were no randomized controlled trials. Of the 69 OCRD participants who had undergone ECT, a positive response was reported in 73.4% of the cases (including 44.0% of the BDD, 74.1% of the tic disorder, and 85.7% of the self-injurious behavior patients). At follow-up, the majority of responders who had abstained from further ECT had experienced relapse. However, a positive response was obtained in all participants who received a new course of ECT. Patients who responded positively to ECT were likely to report previous unsuccessful treatment with antipsychotics (P < .001) and antidepressants (P = .007). The finding that more than 70% of the reviewed cases showed some response to ECT should not be considered unequivocal evidence of its efficacy in OCRDs. The available evidence suggests that a randomized controlled trial of ECT in OCRDs may be warranted, particularly in severe tic disorders and self-injurious behaviors.

Adaptation and validation of the dimensional DSM-5 obsessive-compulsive related disorder scales in adolescents: Preliminary data

The DSM-5 introduced a new chapter called obsessive-compulsive and related disorders (OCRDs), which includes four disorders along with obsessive-compulsive disorder (OCD): body dysmorphic disorder (BDD), hoarding disorder (HD), trichotillomania (hair pulling disorder) (TTM) and excoriation (skin picking) disorder (SPD). The DSM-5 OCRDs subworkgroup developed several short self-report scales for BDD, HD, TTM, and SPD that not only reflect the DSM-5 criteria, but also are consistent in content and structure and can be used by mental health professionals to generate dimensional severity scores for each disorder. The scales were initially validated in adult samples and is therefore unclear if these scales can be reliably used in younger populations. The aim of this study was to examine the psychometric properties of the DSM-5 OCRDs dimensional scales in a sample of 299 Spanish adolescents. The scales showed a one-dimensional structure, acceptable internal consistency (α = 0.69–0.89), convergent validity (rs=0.50–0.71), and significantly higher total values in individuals who indicated the presence of central symptoms of each disorder through diagnostic screening (Cohen's d = 0.65–1.59). The results provide support for further evaluation of these scales in clinical samples of adolescents with OCRDs.

Introduction to the Special Issue: Complexities and New Developments in Adolescent Obsessive-Compulsive Related Disorders

As readers of this special issue will see, the treatments provided in the Obsessive-Compulsive Related Disorder (OCRD) cases described are highly varied. The unifying feature would be better described as an age group rather than a breakdown in inhibitory control as speculated to be the primary unifying mechanism in the OCRD. It is encouraging that effective treatments are emerging for adolescents with OCRDs. Providers will do well to recognize that the appearance of the OCRD does not imply that a treatment for one disorder (i.e., exposure with response prevention [ERP] for OCD) will necessarily also provide relief for another condition in this class (i.e., for Trichotillomania [TM] or Hoarding Disorder [HD]). Instead, given the heterogeneity of these disorders, it comes as little surprise that the interventions are also varied, and providers will require training in a wide range of interventions embedded in sound clinical conceptualization (i.e., Tolin, 2016). It is hoped that these cases will spark additional research on clinical presentations of adolescents with OCRDs.

New perspectives in the treatment of body dysmorphic disorder.

Body dysmorphic disorder (BDD) is a disabling illness with a high worldwide prevalence. Patients demonstrate a debilitating preoccupation with one or more perceived defects, often marked by poor insight or delusional convictions. Multiple studies have suggested that selective serotonin reuptake inhibitors and various cognitive behavioral therapy modalities are effective first-line treatments in decreasing BDD severity, relieving depressive symptoms, restoring insight, and increasing quality of life. Selective serotonin reuptake inhibitors have also recently been shown to be effective for relapse prevention. This review provides a comprehensive summary of the current understanding of BDD, including its clinical features, epidemiology, genetics, and current treatment modalities. Additional research is needed to fully elucidate the relationship between BDD and comorbid illnesses such as obsessive–compulsive-related disorders and depression and to develop therapies for refractory patients and those who have contraindications for pharmacological intervention.

Sensory over-responsivity in trichotillomania (hair-pulling disorder)

ObjectiveThis study was an initial investigation of sensory-over responsivity (SOR) to external sensations among individuals with trichotillomania (TTM). MethodsAdults endorsing DSM-5 TTM criteria (N = 609) and a non-affected comparison sample (N = 268) completed a self-report survey. ResultsThe majority of the TTM group endorsed SOR symptoms; three-quarters endorsed at least mild tactile and auditory SOR. About 15% endorsed SOR symptoms in the severe to extreme range. TTM participants had significantly higher mean scores in both auditory (t (652.89) = −6.51, p < .001, d = .45) and tactile (t (655.24) = −8.38, p < .001, d = .58) modalities than comparison participants, with medium effect sizes. Greater levels of SOR were related to greater levels of perfectionism and by-proxy pulling urges. SOR was significantly and positively correlated with functional impairment when controlling for TTM severity. ConclusionThis study expands prior work in obsessive-compulsive related disorders by contributing the first data about associations between TTM and over-responsivity to external sensations. Findings collectively suggest SOR may be related to maladaptive emotion regulation processes in TTM. A novel measure of SOR was developed and administered in this study.

Body dysmorphic disorder: Latest neuroanatomical and neuropsychological findings.

Body dysmorphic disorder (BDD) is characterized by a preoccupation with a perceived defect or flaw in physical appearance that is not observable or appears slight to others. It leads to severe distress and functional impairment. Cognitive-behavioural and neurobiological similarities to obsessive compulsive disorder (OCD) have led to its newly conceived classification as an obsessive compulsive related disorder (OCRD). In the process of investigating the neurobiology of BDD, neuroimaging and neuropsychological studies have been conducted. This review presents the most recent research findings and their connection with BDD clinical features. Imaging studies have shown increased total white matter volume and caudate volume asymmetry in BDD patients. These findings are consistent with the striatal topography model of OCRDs. Other studies have showed perfusion deficits in bilateral anterior-medial temporal and occipital regions and asymmetric perfusion in parietal lobes. In addition, correlation between symptom severity and left inferior frontal gyrus volume reflects the degree of detailed, analytic encoding that occurs on day-to-day basis when viewing others and themselves, and that likely underlies their symptoms. Finally, positive correlation between right amygdala volume and symptom severity signifies pathological fear circuitry engagement, hypervigilance and heightened sensitivity to social situations. Neuropsychological studies of BDD reveal deficits in strategic organization, learning and free recall after short and long delays. Executive function deficits are related to spatial working memory and subsequent thinking speed as well as impaired higher level planning ability. BDD patients' organizational strategies tend to focus on detail rather than on larger, global clustering features. They are characterized by abnormal visual processing of both details and global elements, inaccurate processing of global elements and reduced flexibility in switching visual attention between global and local features. Moreover, BDD patients seem to have deficits in identifying facial emotional expressions and they tend to misinterpret expressions of disgust (and others) as anger. Poor insight and ideas of reference, common in BDD, might be related to emotion recognition biases for angry expressions. These findings have been supplemented by combined neuroimaging and neuropsychological studies. Left hemisphere hyperactivity for low and normal spatial frequency face tasks and abnormal activation of the amygdala for high and low spatial frequency face tasks suggests detail encoding and analysis in BDD. Patients may primarily perceive details but they are impaired in their ability to contextualize them holistically.

Misophonia: A new mental disorder?

Misophonia, a phenomenon first described in the audiology literature, is characterized by intense emotional reactions (e.g., anger, rage, anxiety, disgust) in response to highly specific sounds, particularly sounds of human origin such as oral or nasal noises made by other people (e.g., chewing, sniffing, slurping, lip smacking). Misophonia is not listed in any of the contemporary psychiatric classification systems. Some investigators have argued that misophonia should be regarded as a new mental disorder, falling within the spectrum of obsessive-compulsive related disorders. Other researchers have disputed this claim. The purpose of this article is to critically examine the proposition that misophonia should be classified as a new mental disorder. The clinical and research literature on misophonia was examined and considered in the context of the broader literature on what constitutes a mental disorder. There have been growing concerns that diagnostic systems such as DSM-5 tend to over-pathologize ordinary quirks and eccentricities. Accordingly, solid evidence is required for proposing a new psychiatric disorder. The available evidence suggests that (a) misophonia meets many of the general criteria for a mental disorder and has some evidence of clinical utility as a diagnostic construct, but (b) the nature and boundaries of the syndrome are unclear; for example, in some cases misophonia might be simply one feature of a broader pattern of sensory intolerance, and (c) considerably more research is required, particularly work concerning diagnostic validity, before misophonia, defined as either as a disorder or as a key feature of some broader syndrome of sensory intolerance, should be considered as a diagnostic construct in the psychiatric nomenclature. A research roadmap is proposed for the systematic evaluation as to whether misophonia should be considered for future editions of DSM or ICD.

Brain derived neurotrophic factor mediated learning, fear acquisition and extinction as targets for developing novel treatments for anxiety

ABSTRACT Anxiety and obsessive-compulsive related disorders are highly prevalent and disabling disorders for which there are still treatment gaps to be explored. Fear is a core symptom of these disorders and its learning is highly dependent on the activity of the neurotrophin brain-derived neurotrophic factor (BDNF). Should BDNF-mediated fear learning be considered a target for the development of novel treatments for anxiety and obsessive-compulsive related disorders? We review the evidence that suggests that BDNF expression is necessary for the acquisition of conditioned fear, as well as for the recall of its extinction. We describe the findings related to fear learning and genetic/epigenetic manipulation of Bdnf expression in animals and BDNF allelic variants in humans. Later, we discuss how manipulation of BDNF levels represents a promising potential treatment target that may increase the benefits of therapies that extinguish previously conditioned fear.

The cost and impact of compulsivity: A research perspective

Compulsivity is the defining feature of various psychiatric disorders including Obsessive Compulsive Related Disorders (OCRDs), and other compulsive, impulsive, and addictive disorders. These disorders are disabling, chronic conditions with an early onset and high rates of comorbidity, misdiagnoses, and delay in treatment onset. Disorders of compulsivity are responsible for considerable socioeconomic burden to society. We review the costs and impacts of compulsivity. In order to facilitate earlier diagnosis and targeted treatments, we examine the overlapping mechanisms that underlie compulsivity. We reconceptualize psychiatric disorders based on core features of compulsivity, highlight challenges in harmonizing research in children and adults, describe newer research methodologies, and point to future directions that can impact the costs and impact of disorders of compulsivity.

Aetiological overlap between obsessive-compulsive related and anxiety disorder symptoms: multivariate twin study.

The aetiological boundary between obsessive-compulsive related disorders (OCRDs) including obsessive-compulsive disorder (OCD) and anxiety disorders is unclear and continues to generate debate. To determine the genetic overlap and the pattern of causal relationships among OCRDs and anxiety disorders. Multivariate twin modelling methods and a new regression analysis to infer causation were used, involving 2495 male and female twins. The amount of common genetic liability observed for OCD symptoms was higher when considering anxiety disorders and OCRDs in the model v. modelling OCRD symptoms alone. OCD symptoms emerged as risk factors for the presence of generalised anxiety, panic and hoarding symptoms, whereas social phobia appeared as a risk factor for OCD symptoms. OCD represents a complex phenotype that includes important shared features with anxiety disorders and OCRDs. The novel patterns of risk identified between OCD and anxiety disorder may help to explain their frequent co-occurrence.

DISTINCT ETIOLOGICAL INFLUENCES ON OBSESSIVE-COMPULSIVE SYMPTOM DIMENSIONS: A MULTIVARIATE TWIN STUDY.

Obsessive-compulsive disorder (OCD) is characterized by five major dimensions, including contamination/washing, harm/checking, symmetry/ordering, hoarding, and forbidden thoughts. How these dimensions may relate etiologically to the symptoms of other obsessive-compulsive related disorders (OCRDs) and anxiety disorders (ADs) is not well known. The aim of this study was to examine the genetic and environmental overlap between each major obsessive-compulsive dimension with the symptoms of other OCRDs and ADs. Two thousand four hundred ninety-five twins of both sexes, aged between 18 and 45 years, were recruited from the Australian Twin Registry. Measures used scores on four dimensions (obsessing (forbidden thoughts), washing, checking, and ordering) of the Obsessive-Compulsive Inventory-Revised, Dysmorphic Concerns Questionnaire, Hoarding Rating Scale, Anxiety Sensitivity Index, Social Phobia Inventory, and Stress subscale of the Depression, Anxiety, and Stress Scale. Multivariate twin modeling methods using continuous and categorized variables were performed, also controlling for age and gender. Our findings suggested that forbidden thoughts and washing demonstrated the strongest genetic overlap with other AD symptoms, while ordering was genetically related to OCRD symptoms. Common genetic influences on checking symptoms were best estimated when modeling OCRDs together with AD symptoms. Common environmental factors of ordering and checking were shared with AD symptoms. Important shared genetic and environmental risk factors exist between OCD, OCRDs, and ADs, but which vary alongside the expression of its major dimensions.