Obsessive-compulsive Spectrum Research Articles

Comprehensive Virtual Treatment for Severe Anxiety in Youth: A Case Report

Anxiety disorders and obsessive-compulsive disorder (OCD) are among the most common mental health conditions in children and adolescents and are associated with various impairments and long-term consequences. Evidence-based treatments exist but are often lacking in elements needed to effectively treat youth with more severe presentations. This case report illustrates a patient’s treatment course in an innovative program for children, adolescents, and young adults with severe anxiety. The program offers a continuum of outpatient, evidence-based care tailored to the severity of the patient’s condition. The case study focuses on “Jane,” an adolescent female with anxiety as well as obsessive-compulsive spectrum disorders, who had previously received extensive treatment without sustained improvement. Through the program’s three treatment phases, Jane and her parents demonstrated consistent engagement and adherence to treatment. Jane showed significant progress, with rapid reduction in symptoms and functional impairment. This case report underscores key elements of this treatment that address gaps in traditional approaches to care, particularly for patients with severe presentations, including the coordinated, team-based approach; the continuum of evidence-based, phased treatment titrated to need; the utilization of virtual individual, group and parent-focused care and between-session coaching to enhance learning generalization; and the use of measurement-based care. Further research is warranted to evaluate the generalizability and long-term outcomes of this program and its potential to transform the treatment landscape for pediatric anxiety and OCD.

Structured clinical interview for diagnosing obsessive-compulsive spectrum disorders.

BackgroundThere are several established structured diagnostic interviews that cover common mental disorders seen in general psychiatry clinics. The administration of more focused diagnostic interviews may be useful in specialty clinics, such as OCD clinics. A semi-structured clinician-administered interview for obsessive-compulsive spectrum disorders (SCID-OCSD) was developed and adapted for DSM-5/ICD-11 obsessive-compulsive and related disorders as well as other putative obsessive-compulsive spectrum conditions. ObjectiveTo introduce a semi-structured diagnostic interview for in-depth assessment of obsessive-compulsive spectrum disorders (OCSDs), and to report on its implementation in adults with primary OCD attending an OCD-specialized unit. MethodsPatients with primary OCD were interviewed using the SCID-OCSD. The SCID-OCSD assesses disorders drawn from several diagnostic categories that share some core features of obsessive-compulsive phenomenology and that are often comorbid in OCD (e.g., obsessive-compulsive related disorders, impulse-control disorders, and a spectrum of compulsive-impulsive conditions such as tics, eating disorders, non-suicidal self-injury, and behavioral addictions. Participants had to be at least moderately symptomatic on the Yale-Brown Obsessive-Compulsive Severity scale (YBOCS, i.e., a total score ≥ 14) to be included in the current study. ResultsOne hundred and one adult patients with current OCD (n = 101, 37 men and 64 women), took part in the study. Forty-two participants (n = 42) had OCD and one or more current or past comorbid OCSDs, with excoriation (skin-picking) disorder (n = 16) and body dysmorphic disorder (n = 14) being the most common. Nine (n = 9) participants reported a history of non-suicidal self-injury, and 6 participants reported a history of comorbid tics. ConclusionsIn OCD clinics, the SCID-OCSD may help diagnose the full range of putative OCSDs, and so facilitate treatment planning and research on these conditions.

Acquired substance-dependent compulsivity but not general compulsivity predicts increased substance use

BackgroundSubstance misuse among college students is a growing area of concern. Approximately 2 in 5 college students suffer from binge drinking disorder, the consequences of which include sexual misconduct, low grade point average (GPA), injury, and even death. Compulsivity is thought to play a key role in the initiation and maintenance of substance use disorder. We aim to clarify the role of compulsivity by evaluating several key components of this construct including rumination and “letting go.”Methods443 undergraduate students participated in an online survey which included measures for substance misuse as well as general measures for compulsivity and a new, adapted measure for substance-dependent compulsivity.ResultsOur findings support our hypothesis that substance-dependent compulsivity, as defined as the drive to consume drugs and/or alcohol specifically, can be used as a behavioral marker to predict substance misuse.ConclusionsSubstance-dependent compulsivity plays a significant role in an unhealthy relationship with substances, including alcohol, above and beyond predisposition for obsessive–compulsive spectrum behavior. Given the age of our study population, it seems then likely that compulsive use of mind-altering substances emerges early in the pathogenesis of substance use disorder.

Psychometric Analysis of the Obsessive-Compulsive Spectrum Self-Report and Social Anxiety Spectrum Self-Report in the Korean Population.

The present study aimed to assess the psychometric properties of the Korean versions of the Obsessive-Compulsive Spectrum Self Report (OBS-SR) and the Social Anxiety Spectrum Self Report (SHY-SR) questionnaires, along with determining their optimal cut-off points in a Korean population. The study included outpatients with obsessive-compulsive disorder (OCD) (n=86), or social anxiety disorder (SAD) (n=52), those with major depressive disorder (MDD) (n=27), and 33 healthy controls. Participants were administered the Korean versions of the OBS-SR and SHY-SR questionnaires. Clinical symptoms were also assessed with several self-rating scales. The Korean versions of the OBS-SR and SHY-SR demonstrated good internal consistency, test-retest reliability, and convergent validity. Both questionnaires effectively differentiated between individuals with OCD or SAD and normal controls or those with MDD. Receiver-operating characteristic analyses of the OBS-SR and SHY-SR yielded area under the curve values of 0.89 and 0.96 for Diagnostic and Statistical Manual of Mental Disorders, Forth Edition diagnosis, respectively, and showed optimal threshold values of 50 and 44. The Korean versions of OBS-SR and SHY-SR demonstrate good reliability and validity in assessing manifestations of obsessive-compulsive and social anxiety psychopathology in Korean populations.

Clinical characteristics of probands with obsessive-compulsive disorder from simplex and multiplex families

Genetic and non-genetic factors contribute to obsessive-compulsive disorder (OCD), with strong evidence of familial clustering. Genomic studies in psychiatry have used the concepts of families that are "simplex" (one affected) versus "multiplex" (multiple affected). Our study compares demographic and clinical data from OCD probands in simplex and multiplex families to uncover potential differences. We analyzed 994 OCD probands (501 multiplex, 493 simplex) from the Brazilian Research Consortium on Obsessive-Compulsive Spectrum Disorders (C-TOC). Clinicians administered the Structured Clinical Interview for DSM-IV (SCID-IV) to diagnose, Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) to assess severity, and Dimensional Yale–Brown Obsessive-Compulsive Scale (DY-BOCS) to assess symptom dimensionality. Demographics, clinical history, and family data were collected. Compared to simplex probands, multiplex probands had earlier onset, higher sexual/religious and hoarding dimensions severity, increased comorbidity with other obsessive-compulsive-related disorders (OCRD), and higher family history of psychiatric disorders. These comparisons provide the first insights into demographic and clinical differences between Latin American simplex and multiplex families with OCD. Distinct clinical patterns may suggest diverse genetic and environmental influences. Further research is needed to clarify these differences, which have implications for symptom monitoring and management.

Serotonergic agonism and pharmacologically-induced adolescent stress cause operant-based learning deficits in mice

BackgroundThe interplay between environmental stress and genetic factors is thought to play an important role in the pathogenesis and maintenance of obsessive-compulsive disorder (OCD). However, the relative contribution of these causative antecedents in the manifestation of cognitive inflexibility—a phenotype often seen in obsessive-compulsive (OC)- spectrum disorders—is not fully understood. MethodIn this study, we treated mice with 50 mg/L corticosterone (CORT, a glucocorticoid stress hormone) in their drinking water during adolescence. In adulthood, we assessed anxiety-like behaviour and locomotor activity; along with operant-based discrimination and reversal learning. RU-24969, a selective serotonin receptor 5-HT1A/1B receptor agonist, was used as an acute pharmacological model of OC-like behaviour. RU-24969 (5 mg/kg) was administered prior to each reversal learning testing session. ResultsWe found that acute treatment with 5 mg/kg RU-24969 induced stereotyped hyperlocomotion in vehicle- and CORT-treated mice. Furthermore, pre-treatment with CORT in adolescence produced subtle anxiety-like behaviour in adult mice, and also resulted in an impairment to late-stage discrimination learning and alterations to reversal learning. Finally, acute treatment with 5 mg/kg RU-24969 caused an impairment to early-stage reversal learning. ConclusionWhilst we revealed dissociable detrimental effects of adolescent CORT treatment and acute 5-HT1A/1B receptor agonism on discrimination and reversal learning, respectively, we did not find evidence of additive deleterious effects of these two treatments. We therefore suggest that while disrupted serotonergic signalling is likely to be involved in the cognitive phenotype of OC-spectrum disorders, distinct neuropathological pathways may be at play in mediating the role of stress as an antecedent in OCD and related illnesses.

A New Explanation: Compensation Mechanism in Comorbidity Disorders of Hoarding Disorder

Hoarding Disorder (HD) is a new category of Obsessive-Compulsive Spectrum Disorder (OCSD). Developing research has provided assessment, phenomenological, and cognitive-behavioral evidence for the independent diagnosis of HD from Obsessive-Compulsive Disorder (OCD). Meanwhile, HD was also found to be comorbid with various other mental disorders with significant impairments for its externality. The paper has reviewed several comorbidity research about HD, aiming to generalize the prevalence and duration of comorbidity disorders in HD conditions. In addition, this paper has also tentatively introduced the concept of compensatory mechanism to interpret the reasons for comorbid conditions in HD, especially the acquisition of specific beliefs or emotional attachments where some Personality Disorders could also form. In conclusion, Generalized Anxiety Disorder (GAD) and Major Depressive Disorder (MDD) are most likely comorbid with HD, whereas posttraumatic stress disorder (PTSD) and Obsessive-Compulsive Personality Disorder (OCPD) might be absent after arguing. Impulse Control Disorder (ICD) could supersede a certain stage of HD with the absence of psychological compensation. Attention Deficit Hyperactive Disorder (ADHD) could also be comorbid with HD on a neurological basis, it could however not conclude that the compensation functions and require further investigation. Based on summarizing and assessing comorbidity disorders in HD, the present paper has provided recommendations for future research development and optimization of therapies.

The Relationship Between Childhood Traumatic Experiences and Obsessive Beliefs in Alcohol Use Disorder

Objective: Based on the pathophysiological similarities between alcohol use disorder (AUD) and obsessive compulsive spectrum disorders, as well as the close association between traumatic experiences and addiction, the goal of this study was to assess the relationship between obsessive beliefs and childhood traumas in patients with alcohol use disorder by comparing them with the control group.
 Material and Method: The data of 60 AUD cases who applied to the Alcohol and Substance Treatment Center (AMATEM) outpatient clinic consecutively and 56 healthy control groups were evaluated. Structured Clinical Interview for DSM-5 (SCID-5), Obsessive Beliefs Questionnaire (OBS), Childhood Trauma Questionnaire (CTS), Hamilton Anxiety Inventory (HAM-A), and Hamilton Depression Inventory (HAM-D) were applied to both groups. The Addiction Profile Index, which evaluates the severity of addiction, was applied to the patient group. Data were evaluated with SPPS 22.
 Results: Obsessive beliefs, traumatic experiences, depression and anxiety scores were found to be significantly higher in AUD cases than in the control group. No significant relationship was found between traumatic experiences and obsessive beliefs. The most important predictors of obsessive beliefs were found to be anxiety and depression scores.
 Conclusion: The current study is valuable because it is the first study to evaluate the relationship between obsessive beliefs and childhood traumas in alcohol use disorder patients. Further analyzes in a larger sample in this area will be helpful in identifying risk factors and creating preventive interventions for AUD, a disorder that is difficult to treat and recurs.

Who really hoards? Hoarding symptoms in adults with attention-deficit hyperactivity disorder (ADHD), obsessive-compulsive disorder (OCD) and healthy controls

Although hoarding disorder (HD) is included in the DSM-5 in the obsessive-compulsive and related disorders chapter, in the last few years, HD has been consistently associated with attention-deficit hyperactivity disorder (ADHD). Some studies on HD patients show higher comorbidity with ADHD than with OCD and some studies on ADHD patients found significant higher rates of HD symptoms compared to the general population. However, the aim of the present study was to be the first direct comparison of the prevalence of HD and HD symptoms across adults with a primary diagnosis of ADHD, OCD and a sample of matched healthy controls (HCs). Methods57 adult patients with a primary diagnosis of ADHD and 50 adult patients with a primary diagnosis of OCD were enrolled and matched with 50 HCs. The presence of hoarding disorder and symptoms were assessed though the Saving Inventory Revised (SI-R). ResultsADHD patients showed significantly higher prevalence of HD comorbidity (32.1%) with respect to both OCD patients (8%) and HCs (4%). The prevalence of HD symptoms was also significantly higher in ADHD patients than in both OCD and HCs. Although OCD patients showed a higher prevalence of HD and HD symptoms with respect to HCs, these differences did not reach statistical significance. ConclusionHD is significantly more comorbid in ADHD patients than in OCD and HCs. A better understanding and definition of the boundaries between HD and the OCD and ADHD spectrum could lead to the development of a more precise treatment approach for hoarding disorder.

Lessons from a multicenter, international, large sample size analysis of patients with obsessive-compulsive disorders: an overview of the ICOCS Snapshot studies.

Obsessive-compulsive disorder (OCD) is a prevalent and highly disabling condition, characterized by a range of phenotypic expressions, potentially associated with geo-cultural differences. This article aims to provide an overview of the published studies by the International College of Obsessive-Compulsive Spectrum Disorders, in relation to the Snapshot database which has, over the past 10years, gathered clinical naturalistic data from over 500 patients with OCD attending various research centers/clinics worldwide. This collaborative effort has provided a multi-cultural worldwide perspective of different socio-demographic and clinical features of patients with OCD. Data on age, gender, smoking habits, age at onset, duration of illness, comorbidity, suicidal behaviors, and pharmacological treatment strategies are presented here, showing peculiar differences across countries.

At the Crossroads between Eating Disorders and Body Dysmorphic Disorders-The Case of Bigorexia Nervosa.

Bigorexia nervosa (BN) is a controversial nosological entity, considered either a feeding/eating disorder (FED) or a subtype of body dysmorphic disorder (BDD). This rapid review aims to explore the characteristic features of BN and identify evidence-based therapeutic interventions for this condition. Three electronic databases (PubMed, Cochrane, and Google Scholar) were searched for relevant information about BN, and 26 reports were reviewed in detail. The results showed that bodybuilders, weightlifters, and other populations involved in athletic activities are the most vulnerable to the onset of this disorder. Patients with BN should also be screened for physical and psychiatric comorbidities and complications, such as anabolic steroid use disorder, physical exercise addiction, and depressive or anxiety disorders. The main differential diagnoses for BN are schizophrenia spectrum disorders, depressive disorders, anxiety disorders, bodily distress disorder, and obsessive-compulsive disorders. Using validated screening instruments is considered very important from a clinical perspective, with the aim of providing early identification of this disorder. Therapeutic interventions for patients with BN are still in the early phases of development, and no specific pharmacological treatment has yet been identified. Since it is similar to the obsessive-compulsive spectrum, cognitive behavioral therapy has been suggested as a useful intervention; however, it has not yet been validated in large-scale clinical trials. In conclusion, based on the reviewed data, clarifying the concept of BN is of practical importance for constructing adequate prevention strategies and validating proper therapeutic interventions.

Validation of the short version of the obsessive compulsive spectrum questionnaire.

In the recent years, a rising amount of research has stressed the importance of a dimensional perspective on mental disorders. In particular, the conceptualization of an obsessive-compulsive spectrum appears to be in line with the very first descriptions of Obsessive-Compulsive Disorder and has been partially acknowledged by the inclusion of the "OCD-spectrum related syndromes and disorders" section in the DSM-5. The goal of the current study is to ascertain the psychometric characteristics of the Obsessive-Compulsive Spectrum-Short Version (OBS-SV), a novel questionnaire designed to measure the complete range of obsessive-compulsive symptoms, from severe full blown to subthreshold ones. Forty three subjects with a clinical diagnosis of OCD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-5); 42 subjects with a clinical diagnosis of social anxiety disorder (SAD), and 60 individuals without current or lifetime mental disorders (HC) were recruited from the Psychiatric Clinic of the University of Pisa. Subjects were assessed with the SCID-5, the Yale Brown Obsessive Compulsive Scale (Y-BOCS) and the OBS-SV. OBS-SV showed strong test-retest reliability for both the total and the domains scores, as well as a high level of internal consistency. The Pearson's coefficients for the OBS-SV domain scores ranged from 0.771 to 0.943, and they were positively and strongly linked with one another (p < 0.001). The OBS-SV total score had a strong correlation with each of the OBS-SV domain scores. All correlation coefficients between OBS-SV and additional measures of OCS were observed to be strong, significant and positive. Both OBS-SV domain and overall score differences between diagnostic groups were found to be statistically significant. From HCs, to the SAD, up to the OC group, which had the highest values, the OBS-SV total score grew dramatically and progressively. The OBS-SV demonstrated significant convergent validity with other dimensional OCD measures, excellent internal consistency, and test-retest reliability. Across the three diagnostic categories, the questionnaire functioned differently, with a rising score gradient from healthy controls through SAD patients to OCD subjects.

Psychometric properties of the Generalised Anxiety Disorder Dimensional Scale in an Australian sample.

The Generalised Anxiety Disorder Dimensional Scale is a new measure of generalised anxiety disorder developed to assist clinicians in the dimensional assessment of generalised anxiety disorder by the Diagnostic and Statistical Manual (Fifth Edition) Anxiety, Obsessive-Compulsive Spectrum, Posttraumatic, and Dissociative Disorder Work Group. This study aims to evaluate the psychometric properties of the scale in an Australian community sample. A sample of 293 Australians (72.7% female) aged between 18 and 73 (M = 28.31 years; SD = 12.11 years) was recruited. Participants completed the Generalised Anxiety Disorder Dimensional Scale, as well as related measures used to assess convergent and discriminant validity. A small proportion of the sample (n = 21) completed the scale a second time to assess test-retest reliability. The scale demonstrated a unidimensional factor structure, good internal consistency (Cronbach's α = .94), good test-retest reliability (ICC = .85), good convergent validity with the Generalised Anxiety Disorder- 7 item (rs = .77), and discriminant validity with the Panic Disorder Severity Scale-Self Report (rs = .63). The scale appears to be a reliable and valid measure of generalised anxiety disorder symptomology for use in the Australian population.

Transcranial magnetic stimulation treatment for dermotillomania: a multidisciplinary approach focused on circuitries and neuroplasticity

Dermotillomania in the Manual for Mental Disorders (DSM5- TR) is included in the chapter "Obsessive-Compulsive Disorders and Related Disorders". Dermotillomania is a disorder characterised by the compulsive damaging of skin tissue through repetitive behaviour. For this reason, patients suffering from this disabling condition are often referred to dermatologists claiming therapy or cosmetic remedies. Repetitive Transcranial Magnetic Stimulation has been approved for the treatment of Obsessive-Compulsive disorder. It has been recently reported to be a promising therapy in other compulsive spectrum disorders, such as trichotillomania and skin picking. According to the "Research Domain Criteria", a circuit-oriented approach targeting the dorsolateral prefrontal cortex to modulate reward and compulsivity circuitries and implied in dermotillomania. A recent report for Obsessive-Compulsive disorder Spectrum Disorders highlights the deleterious effect of inflammation on brain plasticity that affects neuroplasticity and the specific treatment. Given this, some laboratory testing for inflammation has been included in our assessment to reduce the contrast to the therapeutic mechanisms underlying neuroplasticity induced by the Repetitive Transcranial Magnetic Stimulation treatment; this is the first case reporting Repetitive Transcranial Magnetic Stimulation as effective in reducing the dermotillomania to remission. Further studies are needed to validate this proof-of-concept case and this multidisciplinary approach for these disorders, which are not so rare, targeting a brain area highly implicated in the Reward Circuitries.

Obsessions and Delusions: The Clinical Overlap and Differential Diagnosis of Obsessive-Compulsive and Psychotic Disorders

Obsessive-compulsive symptoms (OCS) are commonly observed in the pre-illness, prodromal, first-episode, and chronic stages of schizophrenia. Similarly, patients with obsessive-compulsive disorder (OCD) can present with delusional levels of conviction that border on psychosis. Transitions between OCD and schizophrenia spectrum disorders are also common. The phenomenological overlap between obsessions and delusions can be challenging for accurate diagnosis and treatment planning. Clinicians may struggle to differ entiate obsessions from delusions in severe OCD and similarly may not know if the emerging obsessive symptoms in schizophrenia require specialized OCD treatment. This review summarizes the current literature on comorbid obsessive-compulsive and psychotic disorders, transitions between these two disorders, the impact on prognosis, and the clinical strategies in differential diagnosis as well as treatment planning. [ Psychiatr Ann . 2023;53(5):199–203.]

Diagnosis and therapy of obsessive-compulsive spectrum disorders in general medical and neurological practice

Obsessive-compulsive spectrum disorders are widely represented in the population and often encountered in clinical practice, but they are not well diagnosed and many patients do not receive proper treatment. This review discusses the prevalence of obsessive-compulsive spectrum disorders, their negative impact on the level of functioning of patients, comorbidity with other mental disorders, diagnosis and differential diagnosis. The emphasis is put on changes in approaches to the diagnosis of obsessive-compulsive disorders that will occur after the introduction of the International Classification of Diseases of the 11th revision (ICD-11). Approaches to the treatment of obsessive-compulsive spectrum disorders are discussed in accordance with the principles of evidence-based medicine, and the use of selective serotonin reuptake inhibitors and cognitive behavioral therapy as first-line therapy is justified.

Impaired cognitive flexibility across psychiatric disorders.

Problems with cognitive flexibility have been associated with multiple psychiatric disorders, but there has been little understanding of how cognitive flexibility compares across these disorders. This study examined problems of cognitive flexibility in young adults across a range of psychiatric disorders using a validated computerized trans-diagnostic flexibility paradigm. We hypothesized that obsessive-compulsive spectrum disorders (eg, obsessive-compulsive disorder, trichotillomania, and skin-picking disorder) would be associated with pronounced flexibility problems as they are most often associated with irrational or purposeless repetitive behaviors. A total of 576 nontreatment seeking participants (aged 18-29years) were enrolled from general community settings, provided demographic information, and underwent structured clinical assessments. Each participant undertook the intra-extra-dimensional task, a validated computerized test measuring set-shifting ability. The specific measures of interest were total errors on the task and performance on the extra-dimensional (ED) shift, which reflects the ability to inhibit and shift attention away from one stimulus dimension to another. Participants with depression and PTSD had elevated total errors on the task with moderate effect sizes; and those with the following had deficits of small effect size: generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), antisocial personality disorder, and binge-eating disorder. For ED errors, participants with PTSD, GAD, and binge-eating disorder exhibited deficits with medium effect sizes; those with the following had small effect size deficits: depression, social anxiety disorder, OCD, substance dependence, antisocial personality disorder, and gambling disorder. These data indicate cognitive flexibility deficits occur across a range of mental disorders. Future work should explore whether these deficits can be ameliorated with novel treatment interventions.

Subjective impact of COVID-19 pandemic on youth with tic and OCD spectrum disorders

ObjectivesThis study investigated the perceived impact of the COVID-19 pandemic on youth with chronic tic disorders (CTD) and/or obsessive–compulsive disorder (OCD) based on subjective reports, objective measures, and parental feedback. This study also sought to investigate whether and how these reported experiences differed based on the presence of underlying tic and/or OCD spectrum diagnoses. MethodsChildren with CTD, OCD, and Tics + OCD and their parents were recruited to complete an online survey from July 2020 through April 2021. Forty-eight responses were received; child respondents had a median age of 12 years. ResultsOn average, youth reported that the pandemic negatively impacted them in several domains, particularly after-school activities, relationships with friends, and social/community gatherings. Despite the small sample size, youth with OCD appeared to experience a greater negative impact compared to other subgroups. Median screen use in this sample was 3–8 hours a day, and youth who reported > 8 hours on weekends trended towards increased depressive symptoms. ConclusionConsistent with the physician-authors’ clinical experiences, youth with CTD, OCD, and Tics + OCD and their parents reported a subjective negative impact of the pandemic on various symptoms and psychosocial domains. Going forward, if another lockdown loomed, it would be valuable to stay attuned to these vulnerable youth, particularly those with OCD symptoms, and consider providing support in specific psychosocial domains, such as relationship with peers and home life.

Special Report: Autism Spectrum Disorder and Inflexible Thinking—Affecting Patients Across the Lifespan

Special Report: Autism Spectrum Disorder and Inflexible Thinking—Affecting Patients Across the Lifespan

Obsessive-compulsive symptoms and dissociative experiences: Suggested underlying mechanisms and implications for science and practice.

A strong and specific link between obsessive-compulsive disorder or symptoms (OCD/S) and a tendency for dissociative experiences (e.g., depersonalization-derealization, absorption and imaginative involvement) cannot be explained by trauma and is poorly understood. The present theoretical formulation proposes five different models conceptualizing the relationship. According to Model 1, dissociative experiences result from OCD/S through inward-focused attention and repetition. According to Model 2, dissociative absorption causally brings about both OCD/S and associated cognitive risk factors, such as thought-action fusion, partly through impoverished sense of agency. The remaining models highlight common underlying causal mechanisms: temporo-parietal abnormalities impairing embodiment and sensory integration (Model 3); sleep alterations causing sleepiness and dreamlike thought or mixed sleep-wake states (Model 4); and a hyperactive, intrusive imagery system with a tendency for pictorial thinking (Model 5). The latter model relates to Maladaptive Daydreaming, a suggested dissociative syndrome with strong ties to the obsessive-compulsive spectrum. These five models point to potential directions for future research, as these theoretical accounts may aid the two fields in interacting with each other, to the benefit of both. Finally, several dissociation-informed paths for further developing clinical intervention in OCD are identified.