ØCD: protocol for the development and evaluation of a cognitive-behavioral prevention program for obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) imposes significant burdens on individuals, families, and healthcare systems and the COVID-19 pandemic appears to have exacerbated OCD symptoms. Currently, there are no validated prevention programs for OCD, highlighting a critical gap in mental health services. This study aims to develop and validate the first ØCD prevention program, for at-risk adults, utilizing cognitive-behavioral therapy (CBT) and exposure response prevention (ERP) techniques. METHODS: A single-blind, randomized controlled trial comparing the ØCD prevention program to a waitlist control group will be conducted. Participants, at-risk adults (18-65 years) with subclinical OCD symptoms (OCI-R score ≥ 12), will be recruited for the study. The ØCD prevention program compresise of six online group sessions incorporating CBT and ERP techniques over three modules. The primary outcomes are OCD symptom severity (measured by the Obsessive-Compulsive Inventory- revised form; OCI-R), depression symptoms (measured by the Patient Health Questionnaire; PHQ-9), and anxiety symptoms (measured by the Generalised Anxiety Disorder 7-item; GAD-7). Secondary outcomes include OCD-related beliefs, experiential avoidance, resilience, quality of life, uncertainty intolerance, automatic thoughts, and distress. Outcome measures will be collected at baseline, at completion of the intervention, and one year later (follow-up). At follow-up, we will also analyze the OCD diagnostic incidence, using the Structured Clinical Interview for DSM-5. We will employ a multivariate analysis of variance (MANOVA) to explore whether significant differences exist between groups across dependent variables. To compare the OCD incidence levels from the pre-test to the follow-up we will use the chi-squared test. DISCUSION: The present study may contribute novel data on the efficacy of OCD prevention approaches, leading to the development of an evidence-based OCD prevention program that could alleviate individual and societal burdens associated with OCD. TRIAL REGISTRATION: This trial was approved by the University Ethical Review Authority (937/ 28.11.2023) at Babeș-Bolyai University and is registered on clinicaltrials.gov (ID: NCT06262464).

Efficacy of exposure and response prevention therapy in mixed reality for patients with obsessive-compulsive disorder: study protocol for a randomized controlled trial.

Many patients with obsessive-compulsive disorder (OCD) do not receive cognitive behavioral therapy with exposure and response prevention (first line treatment for OCD), for example, due to patients' fear of the exposure and reservations of the therapists. Technology-supported exposure (e.g., exposure therapy with response prevention in mixed reality [MERP]) for patients with OCD may help to overcome this obstacle. Building upon findings of our pilot study objectives of this study are to evaluate the efficacy, expectations of treatment success, feasibility, and acceptance of MERP as well as to identify possible limitations. In total, 64 outpatients with contamination-related OCD will be recruited and randomized to one of two conditions: MERP (six sessions in six weeks) and self-guided exposure therapy (six exercises in six weeks). Participants will be assessed before (baseline), after the six-week intervention period (post), as well as three months after post assessment (follow-up) regarding symptomatology (Yale-Brown Obsessive Compulsive Scale; Y-BOCS), their subjective evaluation of MERP (acceptance) and sense of presence. The planned study is the first to investigate MERP in patients with OCD.

COVID-19 and OCD: Potential impact of exposure and response prevention therapy.

This brief clinical review critically assesses the use of exposure and response prevention therapy (ERP) for patients with obsessive-compulsive disorder (OCD) in light of the COVID-19 pandemic. We discuss the ethical and practical considerations that clinicians employed in past infectious disease outbreaks, as well as general safety measures routinely practiced in the conduct of exposure therapy. During this time, concerns regarding the feasibility of ERP have emerged, especially with strict guidelines on social distancing and on following other preventative behaviors. While ERP may have to be modified to follow public health guidelines, this review outlines a) how ERP has been adapted in the context of other infectious triggers; b) the potential impacts on OCD patients of attenuated ERP, and c) minimizing concerns related to litigation. A case report is provided detailing ERP personalized given COVID-19 related considerations. In all, we advise against modifying therapies in ways that may jeopardize the efficacy of patient care or progress.

[Othorexia: A new type of Eating Disorder?] / L'orthorexie : une nouvelle forme de trouble des conduites alimentaires ?

Othorexia Nevrosa is defined as an obsessive though regarding healthy food consumption, food properties and cooking tools. Orthorexia Nevrosa is not mentioned in the psychiatric nosography and is not considered as a disorder. While no formal diagnostic criteria currently exist, screening tools have been developed to explore characteristics of Orthorexia Nevrosa. While Orthorexia Nevrosa has specific characteristics, an overlapping exists with Eating Disorders (ED) and Obsessive Compulsive Disorder (OCD) symptoms.

Early intervention for obsessive compulsive disorder: An expert consensus statement.

Obsessive-compulsive disorder (OCD) is common, emerges early in life and tends to run a chronic, impairing course. Despite the availability of effective treatments, the duration of untreated illness (DUI) is high (up to around 10 years in adults) and is associated with considerable suffering for the individual and their families. This consensus statement represents the views of an international group of expert clinicians, including child and adult psychiatrists, psychologists and neuroscientists, working both in high and low and middle income countries, as well as those with the experience of living with OCD. The statement draws together evidence from epidemiological, clinical, health economic and brain imaging studies documenting the negative impact associated with treatment delay on clinical outcomes, and supporting the importance of early clinical intervention. It draws parallels between OCD and other disorders for which early intervention is recognized as beneficial, such as psychotic disorders and impulsive-compulsive disorders associated with problematic usage of the Internet, for which early intervention may prevent the development of later addictive disorders. It also generates new heuristics for exploring the brain-based mechanisms moderating the 'toxic' effect of an extended DUI in OCD. The statement concludes that there is a global unmet need for early intervention services for OC related disorders to reduce the unnecessary suffering and costly disability associated with under-treatment. New clinical staging models for OCD that may be used to facilitate primary, secondary and tertiary prevention within this context are proposed.

Compulsive Digital Gaming: An Emerging Mental Health Disorder in Children.

Excessive digital gaming is emerging as a mental health disorder because youngsters are losing control of their lives by wasting their time by indulging in online multiplayer games. The popularity of the games can be gauged by the fact that India's online gaming market of US $360 million is expected to grow to $ 1 billion by 2021. Video gaming is an obsessive compulsive disorder. The players enjoy creating and building relationships with other online characters, which provides a virtual community feeling at the expense of one-to-one social interactions and real life bonding. In due course of time, the players are preoccupied or "hooked" to the games and display mood swings like irritability, restlessness, and aggressive behavior when they are denied the playing gadgets. Realizing the multifarious health hazards of digital gaming, WHO has recently classified it as a mental health disorder in the 11th revision of its International Classification of Diseases (ICD-11) so that it is accorded the state health benefits for its prevention and treatment. The technology is both a boon as well as a bane, the option is with us. It is important to avoid all obsessions or compulsions in life in order to follow the philosophy of "middle path".

Assisting relapse prevention in OCD using a novel mobile app-based intervention: A case report.

Mobile health apps increase the accessibility of cognitive-behavioral-based interventions before, during, or following treatment. GGOC is a mobile app designed to challenge maladaptive beliefs in obsessive-compulsive disorder (OCD). This single-case study assesses the usefulness of GGOC as a relapse prevention tool for OCD. The patient was a 26-year-old woman with severe contamination and washing/cleaning OCD symptoms (Y-BOCS = 33). GGOC was used for relapse prevention following CBT treatment. The patient completed 47 levels dedicated to OCD-relevant maladaptive beliefs. Before and after GGOC, the Y-BOCS, Obsessive-Compulsive Inventory (OCI-R), Obsessive Beliefs Questionnaire (OBQ-20), and Depression subscale of the Depression, Anxiety, Stress Scale were completed. The OBQ-20 and OCI-R scores decreased from pre- to post-GGOC. The Y-BOCS decreased from 7 pre-GGOC to 2 post-GGOC. Findings support the efficacy of GGOC as a relapse prevention tool for individuals with OCD, and its contribution to maintaining gains after CBT.

Mindfulness-based exposure and response prevention for obsessive compulsive disorder: Findings from a pilot randomised controlled trial.

BACKGROUND: Only about half of people with obsessive compulsive disorder (OCD) show clinically significant improvement following the recommended therapy, exposure and response prevention (ERP), partly due to poor therapy acceptability. A mindfulness-based approach to ERP (MB-ERP) has the potential to improve acceptability and outcomes. METHODS: This was an internal pilot randomised controlled trial (RCT) of group MB-ERP compared to group ERP. 37 participants meeting DSM-IV OCD criteria were randomly allocated to MB-ERP or ERP. RESULTS: Both groups improved in OCD symptom severity. However, MB-ERP did not lead to clinically important improvements in OCD symptom severity at post-intervention compared to ERP - the minimum clinically important difference was not contained in the 95% confidence intervals. There were negligible between-group differences in engagement and MB-ERP did not appear to have broader benefits compared to ERP on depression, wellbeing or OCD-related beliefs. Conversely, MB-ERP led to medium/medium-large improvements in mindfulness compared to ERP. CONCLUSIONS: MB-ERP is unlikely to lead to clinically meaningful improvements in OCD symptom severity compared to ERP alone. We underline the importance of adhering to treatment guidelines recommending ERP for OCD. Insufficient attention may have been given to mindfulness practice/discussion in MB-ERP and further research is recommended to explore this possibility.

Pedophilia-Themed Obsessive-Compulsive Disorder: Assessment, Differential Diagnosis, and Treatment with Exposure and Response Prevention.

Fears of sexually harming children are fairly common among clients suffering from obsessive-compulsive disorder (OCD), yet these symptoms are largely unrecognized and frequently misdiagnosed by mental health professionals. Specifically, clients with pedophilia-themed OCD (P-OCD) experience excessive worries and distressing intrusive thoughts about being sexually attracted to, and sexually violating, children. Expressing these concerns may provoke misjudgments from uninformed mental health professionals that a client is presenting instead with pedophilic disorder. This misdiagnosis and subsequent improper interventions can then contribute to increased fear, anxiety, and in many cases, depression, in affected clients. Therefore, it is imperative that mental health professionals first possess a good understanding of this common manifestation of OCD. As such, in this article, we described obsessions and compulsions typical of P-OCD, in order to inform the reader of the distinctive differences between P-OCD and pedophilic disorder. Information about how to assess for P-OCD symptoms is then provided, followed by suggestions on how to tailor aspects of exposure and response prevention to treat this specific form of OCD.

A call for prevention and early intervention in obsessive-compulsive disorder.

BACKGROUND: Evidence suggests that many people with obsessive-compulsive disorder (OCD) have subclinical symptoms years before the development of their disorder and that early treatment may reduce its severity. AIM: To explore prevention and early intervention strategies for OCD. METHODS: A narrative literature review was conducted. RESULTS: The literature in relation to the prevention of OCD is sparse. Genetic and environmental factors appear to be relevant to the aetiology of OCD, for example, the observation that hoarding symptoms and contamination/cleaning symptoms are more likely to also be present in first-degree relatives. Psychoeducation and the reduction of family accommodation, that is the act of parents, siblings or partners accommodating to the high-risk individual's requests to comply with their compulsions, are promising areas for prevention and early intervention in high-risk groups. Tertiary prevention has also been limited by an inadequate number of trained clinicians to deliver evidence-based treatments. CONCLUSIONS: Much more research is needed in relation to the prevention of OCD. There is limited scope for primary prevention with respect to biological aetiological factors, but there is potential for strategies addressing environmental factors (eg, family factors). The effectiveness of psychoeducation for parents with OCD as a primary prevention strategy for OCD in their children requires scientific evaluation. Improving access to effective treatments for OCD would also improve tertiary prevention.

The Relationship between Obsessive Compulsive Personality and Obsessive Compulsive Disorder Treatment Outcomes: Predictive Utility and Clinically Significant Change.

BACKGROUND: The evidence regarding whether co-morbid obsessive compulsive personality disorder (OCPD) is associated with treatment outcomes in obsessive compulsive disorder (OCD) is mixed, with some research indicating that OCPD is associated with poorer response, and some showing that it is associated with improved response. AIMS: We sought to explore the role of OCPD diagnosis and the personality domain of conscientiousness on treatment outcomes for exposure and response prevention for OCD. METHOD: The impact of co-morbid OCPD and conscientiousness on treatment outcomes was examined in a clinical sample of 46 participants with OCD. RESULTS: OCPD diagnosis and scores on conscientiousness were not associated with poorer post-treatment OCD severity, as indexed by Yale-Brown Obsessive Compulsive Scale (YBOCS) scores, although the relative sample size of OCPD was small and thus generalizability is limited. CONCLUSION: This study found no evidence that OCPD or conscientiousness were associated with treatment outcomes for OCD. Further research with larger clinical samples is required.

Anterior Cingulate Implant for Obsessive-Compulsive Disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is a brain disorder with a lifetime prevalence of 2.3%, causing severe functional impairment as a result of anxiety and distress, persistent and repetitive, unwanted, intrusive thoughts (obsessions), and repetitive ritualized behavior (compulsions). Approximately 40%-60% of patients with OCD fail to satisfactorily respond to standard treatments. Intractable OCD has been treated by anterior capsulotomy and cingulotomy, but more recently, neurostimulation approaches have become more popular because of their reversibility. OBJECTIVE: Implants for OCD are commonly being used, targeting the anterior limb of the internal capsula or the nucleus accumbens, but an implant on the anterior cingulate cortex has never been reported. METHODS: We describe a patient who was primarily treated for alcohol addiction, first with transcranial magnetic stimulation, then by implantation of 2 electrodes overlying the rostrodorsal part of the anterior cingulate cortex bilaterally. RESULTS: Her alcohol addiction developed as she was relief drinking to self-treat her OCD, anxiety, and depression. After the surgical implant, she underwent placebo stimulation followed by real stimulation of the dorsal anterior cingulate cortex, which dramatically improved her OCD symptoms (decrease of 65.5% on the Yale-Brown Obsessive Compulsive Drinking Scale) as well as her alcohol craving (decrease of 87.5%) after 36 weeks of treatment. Although there were improvements in all the scores, there was only a modest reduction in the patient's weekly alcohol consumption (from 50 units to 32 units). CONCLUSIONS: Based on these preliminary positive results we propose to further study the possible beneficial effect of anterior cingulate cortex stimulation for intractable OCD.

Motivaton for change as a predictor of treatment response for dysthymia / Motivación para el cambio como predictor de la respuesta terapéutica en la distimia

OBJECTIVE: Dysthymia constitutes a chronic, mild affective disorder characterized by heterogeneous treatment effects. Several predictors of clinical response and attendance have been postulated, although research on the role of the psychological variables involved in this mental disorder is still scarce. METHOD: Fifty-four adult patients, who met criteria for dysthymia completed an ongoing naturalistic treatment based on the brief interpersonal psychotherapy (IPT-B), which was delivered bimonthly over 16 months. As potential predictor variables, the therapeutic alliance, coping strategies, perceived self-efficacy, and motivation for change were measured at baseline. Outcome variables were response to treatment (Clinical Global Impression and Beck's Depression Inventory) and treatment attendance. RESULTS: stepwise multiple linear regression analyses revealed that higher motivation for change predicted better response to treatment. Moreover, higher motivation for change also predicted treatment attendance. Therapeutic alliance was not a predictor variable of neither clinical response nor treatment attendance. CONCLUSIONS: These preliminary findings support the adjunctive use of motivational interviewing (MI) techniques in the treatment of dysthymia. Further research with larger sample size and follow-up assessment is warranted

OBJETIVO: la distimia constituye un trastorno afectivo crónico caracterizado por una respuesta heterogénea al tratamiento. Se han postulado diversas variables predictoras de dicha respuesta terapéutica, aunque la investigación acerca del papel de las variables psicológicas es todavía escasa. MÉTODO: cincuenta y cuatro pacientes diagnosticados de distimia completaron un tratamiento naturalístico bimensual de 16 meses de duración basado en la psicoterapia interpersonal. Como posibles variables predictoras se evaluó al inicio del tratamiento la alianza terapéutica, las estrategias de afrontamiento, la autoeficacia percibida y la motivación para el cambio. Las variables de tratamiento fueron la respuesta terapéutica (Escala de Impresión Clínica Global e Inventario de Depresión de Beck) y la adherencia terapéutica. RESULTADOS:los análisis de regresión múltiple indicaron que una mayor motivación para el cambio predijo una mejor respuesta al tratamiento. Por otra parte, una mayor motivación para el cambio también predijo una mayor adherencia al tratamiento. La alianza terapéutica no fue una variable predictora ni de la respuesta ni de la adherencia al tratamiento. CONCLUSIONES: estos resultados preliminares apoyan el uso complementario de la entrevista motivacional en el tratamiento de la distimia. Son necesarios estudios adicionales con un mayor tamaño muestral y evaluaciones adicionales durante el seguimiento postratamiento

Schema therapy augmented exposure and response prevention in patients with obsessive-compulsive disorder: Feasibility and efficacy of a pilot study.

BACKGROUND: In spite of the availability of effective treatments for obsessive-compulsive disorder (OCD), many patients do not respond sufficiently or relapse. Treatments using other potentially effective methods such as experiential techniques need to be investigated. We developed a 12-week inpatient treatment augmenting exposure and response prevention (ERP) with schema therapy (ST) called STERP. The feasibility and effectiveness of STERP was tested.. METHODS: In a pilot study, 10 inpatients with OCD who failed to respond to Cognitive Behavioral Therapy (CBT) with ERP received STERP. The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) served as primary outcome. Secondary outcome measures were the Obsessive Compulsive Inventory-revised (OCI-R) and the Beck Depression Inventory (BDI-II). Treatment effects were assessed with t-tests for paired samples. RESULTS: Significant reductions of the Y-BOCS, OCI-R and the BDI-II were found, with very large effect sizes (Cohen's d = 1.48-2.25). Results remained stable at 6 months follow-up. Five prior non-responders responded according to the 35% Y-BOCS symptom reduction criterion.. LIMITATIONS: Lack of control group, small sample size and lack of repeated outcome measures during baseline. CONCLUSIONS: STERP may be a feasible and potentially effective treatment for prior non-responders among OCD patients and thus worth further investigation in randomized controlled trials..

Change in obsessive-compulsive symptoms mediates subsequent change in depressive symptoms during exposure and response prevention.

OBJECTIVE: The current study examines the temporal relationship between changes in obsessive-compulsive symptoms and changes in depressive symptoms during exposure and response prevention (EX/RP) therapy for obsessive-compulsive disorder (OCD). METHOD: Participants were 40 adults (53% female) who received EX/RP in a randomized controlled trial comparing serotonin reuptake inhibitor (SRI) augmentation strategies. Participants completed clinician-administered assessments of OCD (Yale-Brown Obsessive Compulsive Scale) and depressive symptoms (Hamilton Depression Rating Scale) every four weeks from baseline to 32-week follow-up. RESULTS: Lagged multilevel mediational analyses indicated that change in OCD symptoms accounted for 65% of subsequent change in depressive symptoms. In contrast, change in depressive symptoms only partially mediated subsequent change in OCD symptoms, accounting for 20% of the variance in outcome. CONCLUSIONS: These data indicate that reductions in co-morbid depressive symptoms during EX/RP for OCD are largely driven by reductions in obsessive-compulsive symptoms.

Estado de Reposo (Resting State) en Trastorno Obsesivo Compulsivo. Una revisión de la literatura / Resting State in Obsessive-Compulsive Disorder. A review of the literature

Introducción: El trastorno obsesivo compulsivo (TOC) es una enfermedad crónica que puede causar gran impacto en la funcionalidad. El estudio de las neuroimágenes en TOC ha ido avanzando de la mano con el avance de la técnica. Las neuroimágenes funcionales sugieren la participación de la corteza prefrontal y los ganglios basales, formando un sistema córtico subcortical. El estudio del estado de reposo es una nueva técnica radiológica que permite ver la conectividad y actividad de zonas neuronales durante el reposo. Se ha usado en múltiples patologías psiquiátricas, entre ellas TOC. Objetivo: Revisar los estudios de estado de reposo en TOC. Método: Se realizó una búsqueda sistemática en Pub-Med, Scielo y Liliacs, encontrándose 11 trabajos para la revisión. Resultados: TOC sería causado por variaciones en distintos circuitos cerebrales. La percepción constante de error y necesidad de chequeo podría deberse a una hiperconexión interna en la corteza cingulada. La dificultad para el control de las compulsiones podría ser causada por alteraciones a nivel de la corteza prefrontal. No se han encontrado alteraciones propias del TOC y ausentes en controles, las diferencias serían más cualitativas que cuantitativas, siendo el TOC una desregulación de procesos normales

Introduction: Obsessive-compulsive disorder (OCD) is a chronic disease that may have a great impact on functionality. The neuroimaging study on OCD has been advancing along with the advance in the technique. Functional neuroimages suggest the participation of the prefrontal cortex and basal ganglia, forming a subcortical cortex system. Study of the resting state is a new radiological technique that makes it possible to see connectivity and activity of the neuronal zones during rest. It has been used in many psychiatric conditions, among them OCD. Objective: To review the studies on resting state in OCD. Method: A systematic search was made in PubMed, Scielo and Liliacs, and 11 works for found for review. Results: OCD would be caused by variations in different brain circuits. The constant perception of error and checking need could be due to an internal hyperconnection in the cingulate cortex. Difficulty to control compulsions could becaused by alterations on the prefrontal cortex level. No alterations per se of the OCD and absences in controls have been found. The differences would be more qualitative than quantitative, the OCD being a deregulation of normal processes

Parental accommodation of child anxiety and related symptoms: range, impact, and correlates.

Parental accommodation--i.e., changes in parents' behavior in attempts to prevent or reduce child distress--has been most studied in relation to OCD. Although recent work suggests parents of children with non-OCD anxiety diagnoses also engage in accommodation, little is known about the specific forms, correlates, and associated interference of such accommodation. The present study examined the range and associated interference of parental accommodation behaviors using the newly developed Family Accommodation Checklist and Interference Scale (FACLIS) in a sample of the parents of 71 clinic-referred children with anxiety disorders (NMothers-68; NFathers-51). The FACLIS demonstrated good reliability and validity. Ninety-seven percent of mothers and 88% of fathers reported engaging in at least one type of accommodation in the previous two weeks, with parents reporting an average of roughly 4 interfering parental accommodation behaviors. Greater parental accommodation and associated interference were associated with higher maternal distress. Among the anxiety disorders, accommodation was most strongly associated with generalized and separation anxiety disorder, as well as specific phobias. Findings (a) offer psychometric support for the FACLIS as a reliable and valid tool for the assessment of accommodation range and impact, and (b) help clarify the considerable scope and interference associated with parental accommodation of childhood anxiety.

The impact of symptom dimensions on outcome for exposure and ritual prevention therapy in obsessive-compulsive disorder.

OBJECTIVE: Obsessive-compulsive disorder (OCD) is a severe condition with varied symptom presentations. The behavioral treatment with the most empirical support is exposure and ritual prevention (EX/RP). This study examined the impact of symptom dimensions on EX/RP outcomes in OCD patients. METHOD: The Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) was used to determine primary symptoms for each participant. An exploratory factor analysis (EFA) of 238 patients identified five dimensions: contamination/cleaning, doubts about harm/checking, hoarding, symmetry/ordering, and unacceptable/taboo thoughts (including religious/moral and somatic obsessions among others). A linear regression was conducted on those who had received EX/RP (n=87) to examine whether scores on the five symptom dimensions predicted post-treatment Y-BOCS scores, accounting for pre-treatment Y-BOCS scores. RESULTS: The average reduction in Y-BOCS score was 43.0%, however the regression indicated that unacceptable/taboo thoughts (ß=.27, p=.02) and hoarding dimensions (ß=.23, p=.04) were associated with significantly poorer EX/RP treatment outcomes. Specifically, patients endorsing religious/moral obsessions, somatic concerns, and hoarding obsessions showed significantly smaller reductions in Y-BOCS severity scores. CONCLUSIONS: EX/RP was effective for all symptom dimensions, however it was less effective for unacceptable/taboo thoughts and hoarding than for other dimensions. Clinical implications and directions for research are discussed.

Long-term efficacy of Internet-based cognitive behavior therapy for obsessive-compulsive disorder with or without booster: a randomized controlled trial.

BACKGROUND: As relapse after completed cognitive behavior therapy (CBT) for obsessive-compulsive disorder (OCD) is common, many treatment protocols include booster programs to improve the long-term effects. However, the effects of booster programs are not well studied. In this study, we investigated the long-term efficacy of Internet-based CBT (ICBT) with therapist support for OCD with or without an Internet-based booster program. METHOD: A total of 101 participants were included in the long-term follow-up analysis of ICBT. Of these, 93 were randomized to a booster program or no booster program. Outcome assessments were collected at 4, 7, 12 and 24 months after receiving ICBT. RESULTS: The entire sample had sustained long-term effects from pre-treatment to all follow-up assessments, with large within-group effect sizes (Cohen's d = 1.58-2.09). The booster group had a significant mean reduction in OCD symptoms compared to the control condition from booster baseline (4 months) to 7 months, but not at 12 or 24 months. Participants in the booster group improved significantly in terms of general functioning at 7, 12 and 24 months, and had fewer relapses. Kaplan-Meier analysis also indicated a significantly slower relapse rate in the booster group. CONCLUSIONS: The results suggest that ICBT has sustained long-term effects and that adding an Internet-based booster program can further improve long-term outcome and prevent relapse for some OCD patients.