Compulsive rituals in Obsessive-Compulsive Disorder - A qualitative exploration of thoughts, feelings and behavioral patterns.

BACKGROUND AND OBJECTIVES: Rituals are common among healthy individuals and across cultures and often serve adaptive purposes. In individuals with obsessive-compulsive disorder (OCD), rituals become compulsive, time-consuming and distressing, and may lead to functional impairment. Previous research has examined the functions and characteristics of compulsive rituals, but there is paucity of in-depth, first-person reports about this topic. METHOD: We used a qualitative approach to explore thoughts, feelings, and behavioral patterns that characterize OCD rituals. Ten individuals with OCD participated in a semi-structured interview that focused on their most prominent compulsive ritual. The interviews were subjected to a thematic analysis. RESULTS: Eight themes emerged from the analysis and were organized in two main categories: Micro Level perspective, comprising triggers, attention, emotional changes, and stopping criteria; and Macro Level perspective, comprising feelings and perceptions, change over time, motives, and inhibitors. The findings shed light on the role of fixed rules and feelings of "completeness" in OCD rituals, the nature of emotional and attentional characteristics during rituals performance, and the evolution of compulsive rituals over time. LIMITATIONS: This study used a qualitative approach based on a small number of participants, which limits the generalizability of the findings. CONCLUSION: Our results, if replicated, may have clinical implications. The reported patterns of anxiety reduction during ritual performance may contribute to the fine-tuning of CBT for OCD. The findings concerning the nature of attention during ritual performance and the development of rituals over time may be important for understanding the mechanisms that maintain compulsive rituals.

An investigation of the experience of control through the sense of agency in people with obsessive-compulsive disorder: a review and meta-analysis.

The construct of sense of agency (SoA) has proven useful for understanding mechanisms underlying obsessive-compulsive disorder (OCD) phenomenology, especially in explaining the apparent dissociation in OCD between actual and perceived control over one's actions. Paradoxically, people with OCD appear to experience both diminished SoA (feeling unable to control their actions) and inflated SoA (having "magical" control over events). The present review investigated the extent to which the SoA is distorted in OCD, in terms of both implicit (ie, inferred from correlates and outcomes of voluntary actions) and explicit (ie, subjective judgment of one's control over an outcome) measures of SoA. Our search resulted in 15 studies that met the criteria for inclusion in a meta-analysis, where we also examined the potential moderating effects of the type of measure (explicit versus implicit) and of the actual control participants had over the outcome. We found that participants with OCD or with high levels of OCD symptoms show lower implicit measures of SoA and at the same time tend to overestimate their control in situations where they do not actually have it. Together, these findings support the hypothesized dissociation in OCD between actual and perceived control over one's actions.

Brief Interventions for Suicidal Youths in Medical Settings: A Meta-Analysis.

CONTEXT: Most youths who die by suicide have interfaced with a medical system in the year preceding their death, placing outpatient medical settings on the front lines for identification, assessment, and intervention. OBJECTIVE: Review and consolidate the available literature on suicide risk screening and brief intervention with youths in outpatient medical settings and examine common outcomes. DATA SOURCES: The literature search looked at PubMed, OVID, CINAHL, ERIC, and PsychInfo databases. STUDY SELECTION: Interventions delivered in outpatient medical settings assessing and mitigating suicide risk for youths (ages 10-24). Designs included randomized controlled trials, prospective and retrospective cohort studies, and case studies. DATA EXTRACTION: Authors extracted data on rates of referral to behavioral health services, initiation/adjustment of medication, follow-up in setting of assessment, suicidal ideation at follow-up, and suicide attempts and/or crisis services visited within 1 year of initial assessment. RESULTS: There was no significant difference in subsequent suicide attempts between intervention and control groups. Analysis on subsequent crisis service could not be performed due to lack of qualifying data. Key secondary findings were decreased immediate psychiatric hospitalizations and increased mental health service use, along with mild improvement in subsequent depressive symptoms. LIMITATIONS: The review was limited by the small number of studies meeting inclusion criteria, as well as a heterogeneity of study designs and risk of bias across studies. CONCLUSIONS: Brief suicide interventions for youth in outpatient medical settings can increase identification of risk, increase access to behavioral health services, and for crisis interventions, can limit psychiatric hospitalizations.

The Seeking Proxies for Internal States (SPIS) Model of OCD - A Comprehensive Review of Current Findings and Implications for Future Directions.

The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) explains symptoms of OCD as stemming from attenuated access to internal states, which is compensated for by using proxies, which are indices of these states that are more discernible or less ambiguous. Internal states in the SPIS model are subjective states that are not accessible to others, encompassing physiological states, motivations, preferences, memories, and emotions. Compensatory proxies in OCD include fixed rules and rituals as well as seeking and relying on external information. In the present review, we outline the SPIS model and describe its basic tenets. We then use the SPIS conceptualization to explain two pivotal OCD-related phenomena - obsessive doubt and compulsive rituals. Next, we provide a detailed overview of current empirical evidence supporting the SPIS in several domains, including physiological states, emotions, sense of understanding, decision-making, and sense of agency. We conclude by discussing possible neural correlates of the difficulty in accessing internal states, focusing on the anterior insular cortex (AIC) and highlighting potential clinical implications of the model to the treatment of OCD.

Obsessive-Compulsive Symptoms in Children Are Related to Sensory Sensitivity and to Seeking Proxies for Internal States.

Symptoms of obsessive-compulsive disorder are related to atypical sensory processing, particularly sensory over-responsivity, in both children and adults. In adults, obsessive-compulsive symptoms are also associated with the attenuation of access to the internal state and compensatory reliance on proxies for these states, including fixed rules and rituals. We aimed to examine the associations between sensory over-responsivity, the tendency to seek proxies for internal states, and obsessive-compulsive symptoms in children. Parents of 404 children between 5 and 10 years of age completed online measures of obsessive-compulsive symptoms, seeking proxies for internal states, sensory over-responsivity, and anxiety. Linear regression, dominance analysis, and network analysis were used to explore the unique associations between these variables. The tendency to seek proxies for internal states was more strongly associated with obsessive-compulsive symptoms than with anxiety symptoms and uniquely associated with all major obsessive-compulsive symptom dimensions except obsessing. Both the tendency to seek proxies for internal states and sensory over-responsivity were significantly associated with obsessive-compulsive symptoms, but the association was significantly stronger for the tendency to seek proxies for internal states. While limited by the sole reliance on the parent-report, the present study shows that the tendency to seek proxies for internal states could help clarify the developmental processes involved in the onset of obsessive-compulsive symptoms during childhood and that sensory sensitivity may be important to consider in this process.

Attention allocation in OCD: A systematic review and meta-analysis of eye-tracking-based research.

INTRODUCTION: Cognitive models of obsessive-compulsive disorder (OCD) implicate heightened attention allocation to stimuli related to one's obsessions in the disorder. Recently, to overcome several limitations of reaction time-based measures, eye-tracking methodology has been increasingly used in attentional research. METHODS: A meta-analysis of studies examining attention allocation towards OCD-related vs. neutral stimuli, using eye-tracking methodology and a group-comparison design, was conducted conforming to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Separate meta-analyses were performed for attentional vigilance (both latency and location of first fixations) and maintenance (total dwell time and total fixation count, conjointly). Each meta-analysis was conducted twice - once including all studies (main analysis) and once only including studies using the free-viewing paradigm (secondary analysis). RESULTS: The systematic search yielded a total of nine studies. Of those, eight provided the needed data to be included in the meta-analysis. No evidence emerged for vigilance via latency to first fixation. Vigilance reflected via first fixation location emerged in the main analysis, but not in the secondary one. Evidence for attentional maintenance was found only when analyzing free-viewing studies exclusively (the secondary analysis). LIMITATIONS: To increase the accuracy of the research question, correlational studies were excluded, resulting in a small number of available studies. CONCLUSIONS: OCD may be characterized by vigilance, but mainly in tasks entailing specific demands and/or goals. Conversely, attentional maintenance may be evident only when using tasks that pose no requirements or demands for participants.

Are people with obsessive-compulsive disorder under-confident in their memory and perception? A review and meta-analysis.

People with obsessive-compulsive disorder (OCD) tend to distrust their memory, perception, and other cognitive functions, and many OCD symptoms can be traced to diminished confidence in one's cognitive processes. For example, poor confidence in recall accuracy can cause doubt about one's memory and motivate repeated checking. At the same time, people with OCD also display performance deficits in a variety of cognitive tasks, so their reduced confidence must be evaluated in relation to their actual performance. To that end, we conducted an exhaustive review and meta-analysis of studies in which OCD participants and non-clinical control participants performed cognitive tasks and reported their confidence in their performance. Our search resulted in 19 studies that met criteria for inclusion in the quantitative analysis, with all studies addressing either memory or perception. We found that both performance and reported confidence were lower in OCD than in control participants. Importantly, however, confidence was more impaired than performance in participants with OCD. These findings suggest that people with OCD are less confident in their memory and perception than they should be, indicating a genuine under-confidence in this population. We discuss potential mechanisms that might account for this finding and suggest avenues for further research into under-confidence and related meta-cognitive characteristics of OCD.

Attenuated Access to Emotions in Obsessive-Compulsive Disorder.

The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) posits that OCD is associated with attenuated access to internal states. Here we explored the implications of this model in the realm of emotions. Participants with OCD, anxiety disorders, and nonclinical control participants completed the Mayer-Salovey-Caruso Emotional Intelligence Test (MSCEIT), assessing two domains of emotional intelligence: Experiential emotional intelligence (EI), reflecting the ability to perceive and feel emotions accurately, and Strategic EI, reflecting the ability to understand and manage emotions correctly. As only Experiential EI requires accurate perception of one's emotions for adequate performance, we predicted an interaction between group and EI area. Specifically, we predicted that compared to both anxiety disorders and healthy control participants, OCD participants would show a larger deficit in Experiential area of the MSCEIT relative to the Strategic area. Results were fully in line with this prediction. Moreover, supporting the specificity of the hypothesized deficit to OCD, participants with anxiety disorders did not differ from nonclinical control participants in their performance, and findings were not attributable to anxiety or depression levels. These results replicate and extend previous findings obtained with analogue samples and suggest that OCD is associated with attenuated access to emotional states, which may be partially compensated for by reliance on semantic knowledge of emotion.

Seeking proxies for internal states (SPIS): Towards a novel model of obsessive-compulsive disorder.

The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) proposes an account of OCD symptoms in terms of two core components: attenuation of access to internal states and seeking proxies for internal states. Specifically, the SPIS model posits that OCD is associated with difficulty in accessing various internal states, including feelings, preferences, memories, and even physiological states. This difficulty drives obsessive-compulsive individuals seek and rely on compensatory proxies, or substitutes, for their internal states. These proxies are perceived by the individual with OCD to be more easily discernible or less ambiguous compared to the internal states for which they substitute, and can take the form of fixed rules, rituals, or reliance on external sources of information. In the present article we first provide a detailed explanation of the SPIS model, and then review empirical studies that examined the model in a variety of domains, including bodily states, emotions, and decision-making. Next, we elaborate on the SPIS model's novel account of compulsive rituals, obsessions and doubt and relate them to extant theoretical accounts of OCD. To conclude, we highlight open questions that can guide future research and discuss the model's clinical implications.

Intact capacity for implicit learning in obsessive-compulsive disorder.

BACKGROUND AND OBJECTIVES: Individuals with OCD tend to rely on explicit processing when performing implicit learning tasks. However, it is unclear whether this tendency reflects impaired capacity for implicit processing or a preference toward explicit processing. We sought to use a psychometrically valid task to examine the hypothesis that individuals with OCD have intact capacity for implicit learning. METHODS: Twenty-four participants with OCD and 24 non-psychiatric controls completed a modified artificial grammar learning task where acquisition and retrieval of the underlying grammatical rules are considered strictly implicit. In an exploratory condition designed to examine the effect of nudging participants toward controlled processing, 12 participants in each group were told that the stimuli presented at acquisition were composed according to grammatical rules and were encouraged to identify these rules. RESULTS: As predicted, participants with OCD acquired and expressed knowledge of the grammatical rule, demonstrating intact capacity for implicit learning, with no differences found between the OCD and controls on the extent of implicit learning. The exploratory intentional learning instructions had no effect, as participants in this condition were unable to adhere to the instructions, supporting the robust implicit nature of the artificial grammar learning task. LIMITATIONS: The relatively small sample size did not allow comparisons between OCD symptom subtypes. CONCLUSIONS: Our results provide evidence for intact implicit learning in OCD, and challenge previous studies suggesting a general deficiency in implicit learning in OCD.

Is disgust in obsessive-compulsive disorder mediated by fear of pathogens?

Individuals with obsessive-compulsive disorder (OCD) tend to report higher levels of disgust, but not much is known about factors that might underlie this relationship. The present study was motivated by the behavioral immune theory, which suggests that disgust has evolved as a protective reaction to potential presence of disease agents in the immediate environment. We examined the relationships between the intensity of experienced physical disgust, perceived vulnerability to disease, and OCD symptoms. The intensity of experienced disgust was assessed with a recent procedure whereby participants rate how disgusted they feel in response to color versus black-and-white pictures that evoke physical disgust. In addition to this procedure, participants (N = 403) completed measures of perceived vulnerability to disease, OCD symptoms, depression and anxiety. OCD symptoms were positively related to the physical disgust evoked by the pictures, and this relationship was mediated by reported emotional discomfort in contexts that connote a potential for pathogen transmission. Replicating previous findings, color pictures were rated as more disgusting than black-and-white pictures overall, and this effect was especially pronounced among people with higher OCD tendencies. These results suggest that, consistent with behavioral immune theory, disgust in OCD is a basic, concrete emotion that is at least partly mediated by fear of pathogens.

Obsessive-compulsive symptoms are related to reduced awareness of emotional valence.

BACKGROUND: The Seeking Proxies for Internal States (SPIS) model of OCD asserts that obsessive-compulsive (OC) tendencies are associated with attenuated access to internal states. Here we explore the implications of this model for awareness of emotional valence. METHODS: In Study 1, participants with high and low OC tendencies (n = 30 in each group) rated how they felt while viewing different pictures with positive, neutral, or negative valence taken from the International Affective Picture System. Study 2 replicated Study 1 among non-selected participants (n = 99) that rated positive and negative pictures chosen from the recently developed Basic-Emotions Nencki Affective Picture System. In both studies, mean deviation from norm ratings (of each picture system) served as the primary outcome measure. RESULTS: Study 1 showed that high OC participants' mean deviation score was significantly higher, compared with low OC participants, across positive, neutral, and negative pictures (p=.01). Follow-up analyses revealed that while no group difference emerged for mean valence rating (p=.16), groups differed on the mean standard deviation of ratings within each valence category (p=.002). In Study 2, only OC tendencies, not depressive or anxiety symptoms, were positively correlated with mean deviation from norm ratings (p=.026). Dividing the sample to high and low OC groups based on an OC cutoff score yielded similar group differences to those observed in Study 1 (p<.001). LIMITATIONS: Analog samples and a relative small sample size (Study 1). CONCLUSIONS: This study suggests that OC symptoms are associated with reduced awareness of emotional valence, possibly emanating from a noisier emotional perception.

Attenuation of access to internal states in high obsessive-compulsive individuals might increase susceptibility to false feedback: Evidence from a visuo-motor hand-reaching task.

BACKGROUND AND OBJECTIVES: The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) posits that obsessive-compulsive (OC) individuals have attenuated access to their internal states. Hence, they seek and rely on proxies, or discernible substitutes for these internal states. In previous studies, participants with high OC tendencies and OCD patients, compared to controls, showed increased reliance on external proxies and were more influenced by false feedback when judging their internal states. This study is the first to examine the effects of false feedback on performance of hand movements in participants with high and low OC tendencies. METHOD: Thirty-four participants with high OC tendencies and 34 participants with low OC tendencies were asked to perform accurate hand reaches without visual feedback in two separate sessions of a computerized hand-reaching task: once after valid feedback training of their hand location and once with false-rotated feedback. We assessed the accuracy and directional adaptation of participants' reaches. RESULTS: As predicted, high OC participants evidenced a larger decrease in their hand positioning accuracy after training with false feedback compared to low OC participants. LIMITATIONS: The generalization of our findings to OCD requires replication with a clinical sample. CONCLUSIONS: These results suggest that in addition to self-perceptions, motor performance of OC individuals is prone to be overly influenced by false feedback, possibly due to attenuated access to proprioceptive cues. These findings may be particularly relevant to understanding the distorted sense of agency in OCD.

Obsessive-compulsive tendencies predict seeking proxies for understanding.

BACKGROUND AND OBJECTIVES: The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) postulates that obsessive-compulsive (OC) individuals have reduced access to their internal states and must therefore seek and rely on external proxies for these states. The present study extended this hypothesis to the feeling of understanding, which had not been examined previously in relation to OCD. METHODS: We presented 148 participants with a computerized task requiring them to read and understand a text on medieval architecture. Participants were randomly assigned to an ongoing feedback condition (comprehension quiz and answers provided after each text segment) or no-feedback condition (quiz and answers provided only at the end). Throughout, participants were offered proxies in the form of "learning aids," which were unrelated to text comprehension. Participants were divided to high vs. low OC tendencies based on a median split on a measure of OCD symptoms. RESULTS: As predicted, lacking feedback on understanding was associated with higher use of proxies and high OC participants used more proxies than low OC participants in the no-feedback condition. Actual understanding, as assessed by comprehension scores, was unrelated to OC tendencies. LIMITATIONS: Among other limitations discussed in the article, our results were obtained on a non-selected sample of students varying on OC tendencies. It would be important to replicate these findings with diagnosed OCD participants as compared to both non-clinical and anxiety disorders control participants. CONCLUSIONS: These findings extend the SPIS model to the domain of understanding and may have important clinical implications.

Congruence and discrepancy between self-rated and clinician-rated symptom severity on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) before and after a low-intensity intervention.

The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) is the most common measure of Obsessive-Compulsive symptom severity. The Y-BOCS interview is considered gold standard, but its self-rating format is increasingly used in clinical trials. Few studies investigated congruency and potential changes over treatment. This question is highly relevant, as a systematic bias might obscure results of clinical trials. We examined the relationship of self- and clinician-rated Y-BOCS scores in participants with obsessive-compulsive disorder in pre (N = 128), post, (4 weeks, n = 104) and follow-up (6 months, n = 98) assessments of a randomized-controlled clinical trial. We administered Y-BOCS interview via telephone paralleling online administration of the self-report form. Analyses showed medium-to-strong correlations of Y-BOCS interview and self-rating scores at pre-assessment. Patients rated symptoms lower than clinicians. Larger discrepancies were associated with hoarding and age. Congruency was inferior for obsessions relative to compulsions, largely owing to the "resistance against obsessions" item. Agreement strongly increased at post and follow-up. Though overall congruency between the two Y-BOCS forms was satisfactory, results suggest a "correction over time" effect. Such bias may distort the precise interpretation of treatment effects. Therefore, we made several suggestions to improve the reliability of change scores assessed with the Y-BOCS self-rating.

Obsessive-compulsive tendencies are related to seeking proxies for internal states in everyday life.

BACKGROUND AND OBJECTIVES: In recent years we have proposed and investigated the Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD), which postulates that deficient access to internal states is a key feature of the disorder. According to this model, rules and rituals that often characterize people with OCD can be understood as proxies for deficiently accessible internal states. Here we compliment this earlier experimental work by examining whether reliance on proxies for internal states in everyday life is associated with OCD. METHODS: We developed an inventory for assessing reliance on proxies in everyday life and examined its relationship with obsessive-compulsive tendencies in two internet panel studies. The internal states included hunger, enjoyment, interpersonal liking, preferences, a sense of understanding, and intuitions about correct solutions to problems. The proxies included one's own behavior, the opinion of others, and objective indices such as grades and elapsed time since eating. RESULTS: In both studies, participants with obsessive-compulsive tendencies reported relying more on external, discernible proxies for a variety of internal states. These results remained significant after controlling for concurrent anxiety and depression. LIMITATIONS: Our inventory is by necessity limited in its sampling of internal states and proxies and further correlational and experimental studies will be needed to examine additional areas of application, such as decision making and interpersonal liking. CONCLUSIONS: These results are consistent with and expand the Seeking Proxies for Internal States (SPIS) model and may have implications for understanding and treating individual with OCD.

Obsessive-Compulsive Tendencies Are Related to a Maximization Strategy in Making Decisions.

The present studies were motivated by the hypothesis that attenuated access to internal states in obsessive-compulsive (OC) individuals, which leads to extensive reliance on external proxies, may manifest in a maximizing decision making style, i.e., to seeking the best option through an exhaustive search of all existing alternatives. Following previous research, we aimed to explore the possible relationships between OC tendencies, seeking proxies for internal states, indecisiveness and maximization. In Study 1, we measured levels of OC tendencies, seeking proxies for internal states, indecisiveness, maximization, depression and anxiety in an online Hebrew speaking sample (N = 201). In Study 2, we administrated the same questionnaires to an online English speaking sample (N = 240) and in addition, examined participants' decision making strategies in a hypothetical situation. The participants in both studies were unscreened adults. Correlational and linear regressions analyses indicated that OC tendencies are related to maximization, even when levels of indecisiveness, depression and anxiety are controlled for. Moreover, the findings suggested that reliance on external proxies may partially account for the aforementioned association. Possible implications and future directions are discussed.

Explicit instructions facilitate performance of OCD participants but impair performance of non-OCD participants on a serial reaction time task.

Previous studies have shown that individuals diagnosed with OCD tend to rely on explicit processing while performing implicit learning tasks. We sought to investigate whether individuals with OCD are capable of implicit learning, but would demonstrate improved performance when explicit processing strategies are enhanced. Twenty-four participants with OCD and 24 non-psychiatric control (NPC) participants performed an implicit learning task in which they responded to a single target stimulus that successively appears at one of four locations according to an underlying sequence. We manipulated the learning strategy by informing half of the participants that the target stimulus location was determined by an underlying sequence, which they should identify (intentional learning). The other half of the participants was not informed of the existence of the underlying sequence, and was expected to learn the sequence implicitly (standard learning). We predicted that OCD participants will exhibit inferior performance compared to NPC participants in the standard learning condition, and that intentional learning instructions would impair the performance of NPC participants, but enhance the performance of OCD participants. The results supported these predictions and suggest that individuals with OCD prefer controlled to automatic processing. We discuss the implications of this conclusion to our understanding of OCD.

High obsessive-compulsive individuals may have attenuated access to internal cues associated with active movement: Evidence from a head repositioning study.

BACKGROUND AND OBJECTIVES: The Seeking Proxies for Internal States model of OCD posits that obsessive-compulsive (OC) individuals have attenuated access to their internal states. Consequently, they seek and rely on discernible substitutes for these internal states. Previous research has supported these conjectures. Other studies, using a variety of measures, reported a reduced sense of agency (SoA) in OCD. The current study aimed to connect these two bodies of research by focusing on internal signals associated with active movement, which are related to the SoA. We hypothesized that the performance accuracy of high OC participants would be similar for active and passive movements, while that of low OC participants would be higher when the movement is acquired actively. METHOD: Participants with high vs. low OC tendencies were asked to reposition their head to a target angle that was acquired actively or passively. This was repeated with eyes blindfolded to evaluate reliance on visual information. Accuracy of repositioning was measured with a cervical range-of-motion device. RESULTS: As predicted, while low OC participants presented a significant decrease in their accuracy after passive (compared to active) acquisition, high OC participants' accuracy did not differ between acquisition types. Contrary to our predictions, reliance on vision was similar across groups. LIMITATIONS: The generalization of our findings to OCD requires replication with a clinical sample. CONCLUSIONS: This study implies that high OC individuals have a deficient access to internal cues involved in active movement. This might contribute to their doubt regarding their actions and to their reduced SoA.

Clinical and electrophysiological outcomes of deep TMS over the medial prefrontal and anterior cingulate cortices in OCD patients.

BACKGROUND: Obsessive Compulsive Disorder (OCD) is a chronic and disabling disorder with poor response to pharmacological treatments. Converging evidences suggest that OCD patients suffer from dysfunction of the cortico-striato-thalamo-cortical (CSTC) circuit, including in the medial prefrontal cortex (mPFC) and the anterior cingulate cortex (ACC). OBJECTIVE: To examine whether modulation of mPFC-ACC activity by deep transcranial magnetic stimulation (DTMS) affects OCD symptoms. METHODS: Treatment resistant OCD participants were treated with either high-frequency (HF; 20 Hz), low-frequency (LF; 1 Hz), or sham DTMS of the mPFC and ACC for five weeks, in a double-blinded manner. All treatments were administered following symptoms provocation, and EEG measurements during a Stroop task were acquired to examine changes in error-related activity. Clinical response to treatment was determined using the Yale-Brown-Obsessive-Compulsive Scale (YBOCS). RESULTS: Interim analysis revealed that YBOCS scores were significantly improved following HF (n = 7), but not LF stimulation (n = 8), compared to sham (n = 8), and thus recruitment for the LF group was terminated. Following completion of the study, the response rate in the HF group (n = 18) was significantly higher than that of the sham group (n = 15) for at least one month following the end of the treatment. Notably, the clinical response in the HF group correlated with increased Error Related Negativity (ERN) in the Stroop task, an electrophysiological component that is attributed to ACC activity. CONCLUSION: HF DTMS over the mPFC-ACC alleviates OCD symptoms and may be used as a novel therapeutic intervention. Notwithstanding alternative explanations, this may stem from DTMS ability to directly modify ACC activity.