About

Steven A. Rasmussen, MD, MMS is a Professor of Psychiatry and Human Behavior and serves as the Chair of the Department of Psychiatry and Human Behavior at the Alpert Medical School of Brown University. He is an internationally recognized expert in the course and treatment of obsessive compulsive disorder (OCD). His primary research interests include neurosurgical approaches to intractable OCD and depression, the neurocircuitry of OCD, and the longitudinal course of OCD. Dr. Rasmussen has authored or coauthored over 100 peer-reviewed publications and has been actively involved in studies funded by multiple R01 grants from the NIMH, focusing on understanding the neurobiological underpinnings of OCD and related conditions. He has contributed significantly to bridging campus-based and hospital-based brain science faculty at Brown University, advancing research and clinical care in psychiatric neuroscience.

Research topics

• Psychology
• Medicine
• Radiology
• Neuroscience
• Internal medicine
• Surgery

Selected publications

• A study of alcohol dependence in obsessive-compulsive disorder

  Journal of Psychiatric Research · 2026-04-06

  article
  PublisherDOI

• Medial prefrontal-thalamic white matter microstructure is associated with harm avoidance in OCD: a discovery and transdiagnostic replication study

  Neuropsychopharmacology · 2026-01-31

  articleOpen access

  Identifying neural mechanisms underlying harm avoidance and incompleteness in OCD and other psychiatric disorders is critical for improving diagnostic precision and developing targeted treatments. However, little is known about the neural pathways underlying these symptom dimensions across clinical populations. The goal of this study was to use diffusion MRI to replicate and extend prior findings in OCD to a transdiagnostic sample of healthy controls (HC) and individuals with Obsessive-Compulsive Disorder (OCD), Obsessive-Compulsive Personality Disorder (OCPD), and non-OCD disorders (e.g., anxiety, post-traumatic stress disorder). Connections between prefrontal (dorsomedial, dorsolateral, ventromedial, and ventrolateral) and subcortical regions (thalamus and striatum) were reconstructed using whole brain tractography in 38 HC (mean age [SD] = 30.97 [10.62), 47 OCD (mean age [SD] = 32.34 [12.23]), 21 OCPD (mean age [SD] = 35.67 [14.65]), and 20 Non-OCD (mean age [SD] = 35.90 [14.26]) participants. Fractional anisotropy (FA) was derived for each connection. Harm avoidance and incompleteness symptom dimensions were assessed using the Obsessive-Compulsive Trait Core Dimensions Questionnaire. In a first replication model, including individuals with OCD and HC, higher left (β = 0.29, P = 0.009, Q = 0.048) and right (β = 0.30, P = 0.005, Q = 0.0048) dorsomedial PFC-thalamus FA was associated with higher harm avoidance, with the left connection also associated with higher incompleteness (β = 0.29, P = 0.009, Q = 0.048). In additional models adding in OCPD and non-OCD participants, only associations among left (β = 0.20, P = 0.027, Q = 0.040) and right (β = 0.18, P = 0.035, Q = 0.045) dorsomedial PFC-thalamus FA and harm avoidance remained significant. There were no associations involving PFC-striatum connections. Dorsomedial PFC-thalamus FA was associated with harm avoidance, but less so with incompleteness. Our findings suggest that higher dorsomedial PFC-thalamic FA is associated with higher harm avoidance across diagnostic groups, providing transdiagnostic neural targets for future treatment developments.

  PublisherOA PDFDOI

• Seven-Year Stability of Obsessive-Compulsive Personality Disorder Symptom Criteria in Individuals with Obsessive Compulsive Disorder

  Personality Disorders Theory Research and Treatment · 2025-06-06

  preprintOpen access

  Obsessive-compulsive disorder (OCD) commonly co-occurs with personality disorders, particularly obsessive-compulsive personality disorder (OCPD). Recent research suggests that personality disorders, especially OCPD, might not be as stable as once thought. The current study investigates the longitudinal stability of OCPD diagnosis and individual symptom criteria in individuals with OCD. Around 320 participants with a primary diagnosis of OCD were included in the study, with diagnostic assessments conducted annually for 7 years. Logistic mixed-effects models were conducted to examine the relationship between time and OCPD diagnosis ratings, as well as the relationship between time and each OCPD symptom criterion over 7 years. In individuals with OCD, time was a significant predictor of OCPD diagnosis which indicated diagnostic instability, with the likelihood of OCPD diagnosis decreasing over time. Three individual criteria (detail-oriented, inflexible, overconscientious, and scrupulous, and miserly spending style) were shown to be stable while the other five (perfectionism, reluctance to delegate, rigidity and stubbornness, excessive work devotion, and inability to discard) were unstable. OCPD diagnosis ratings generally remained stable with some decrease over time in individuals with OCD and consist of a mix of enduring and episodic symptom criteria. It suggests the need for a refinement of OCPD diagnostic criteria and future research on symptom stability of OCPD across different diagnostic groups. (PsycInfo Database Record (c) 2026 APA, all rights reserved).

  PublisherDOI

• Stability and Transition Likelihood of Primary Symptoms in Adults with Obsessive-Compulsive Disorder: A 5-Year Prospective Follow-Up Study

  2025-04-04

  preprint

  Background: Obsessive-compulsive disorder (OCD) has a chronic course. However, limited longitudinal research exists on whether adults with OCD tend to maintain the same cluster of symptoms and how those symptoms may change over time. The present study aimed to examine the stability of primary OCD symptoms across 5 years and describe how symptoms change within individuals.Methods: 107 treatment-seeking adults with primary OCD participated in a naturalistic prospective study on the course of OCD. Primary obsessions and compulsions were assessed using the Yale-Brown Obsessive Compulsive Scale at baseline, year 2, and year 5. Markov transition probabilities were calculated to assess the likelihood of symptom change from one of the nine primary obsession categories and seven compulsion categories to another at follow-up. Results: Symptom stability varied across categories. Contamination, hoarding, symmetry, and responsibility for harm obsessions were generally stable, along with hoarding, cleaning, and checking compulsions. Conversely, somatic, aggressive, religious, sexual, and miscellaneous obsessions tended to change, along with repeating, counting, and ordering/arranging compulsions. Aggressive, religious, and sexual obsessions most often switched to one of the other two categories at follow-up. Overall, OCD symptom stability decreased over longer follow-up periods. Limitations: Symptom stability was only assessed between baseline and years 2 and 5. Therefore, possible changes between years 2 and 5 remain unclear.Conclusions: OCD symptoms are relatively stable over time; however, specific symptoms may be more likely to vary. Future research should investigate factors underlying stable and unstable symptoms, as well as the impact of treatment on symptom stability.

  PublisherDOI

• Moving beyond symptom subtypes: testing a common dimension of lifetime OCD symptoms

  CNS Spectrums · 2025-01-01

  articleOpen access

  INTRODUCTION: Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder characterized by recurrent intrusive thoughts and ritualized behaviors, often aimed at reducing distress. OCD is heterogeneous in its presentation and many patients with OCD experience a variety of different symptoms throughout their course of illness. Efforts to understand symptom domains in OCD have typically identified three to five symptom domains, such as the domains of doubt/checking, contamination, superstitions/rituals, symmetry/hoarding, and taboo thoughts. Recent studies in the genetics of OCD have suggested a common OCD dimension may provide additional information above and beyond the previously identified symptom domains. Thus, we sought to test a hierarchical model of lifetime OCD symptoms and evaluate the utility of the inclusion of a common OCD dimension. METHODS: Participants included 999 individuals participating in the OCD Collaborative Genetics Study (OCGS) and an additional 2363 individuals participating in the OCD Genetic Association Study (OCGAS). We evaluated unidimensional, 5-factor, and hierarchical models of lifetime OCD symptom presentation using confirmatory factor analysis. RESULTS: Results suggested that the hierarchical model best fit the data. Further evaluation of these models using a Bayesian testlet response model showed that lifetime presence of specific OCD symptoms was differentially associated with lifetime OCD severity. Moreover, symptoms associated with greater lifetime severity were generally reported less frequently than symptoms present at lower levels of lifetime severity. Implications of these findings and future directions are discussed.

  PublisherOA PDFDOI

• Stability and transition likelihood of primary symptoms in adults with obsessive-compulsive disorder: A 5-year prospective follow-up study

  Journal of Affective Disorders · 2025-04-05 · 5 citations

  article
  PublisherDOI

• Seven-Year Stability of Obsessive-Compulsive Personality Disorder Symptom Criteria in Individuals with Obsessive Compulsive Disorder

  2025-11-07 · 1 citations

  article

  Background: Obsessive-compulsive disorder (OCD) commonly co-occurs with personality disorders, particularly obsessive-compulsive personality disorder (OCPD). Recent research suggests that personality disorders, especially OCPD, might not be as stable as once thought. The current study investigates the longitudinal stability of OCPD diagnosis and individual symptom criteria in individuals with OCD. Methods: 320 participants with a primary diagnosis of OCD were included in the study, with diagnostic assessments conducted annually for seven years. Logistic mixed-effects models were conducted to examine the relationship between time and OCPD diagnosis ratings, as well as the relationship between time and each OCPD symptom criterion over seven years. Results: In individuals with OCD, time was a significant predictor of OCPD diagnosis which indicated diagnostic instability, with the likelihood of OCPD diagnosis decreasing over time. Three individual criteria (detail-oriented, inflexible, overconscientious, and scrupulous, and miserly spending style) were shown to be stable while the other five (perfectionism, reluctance to delegate, rigidity and stubbornness, excessive work devotion, and inability to discard) were unstable. Conclusion: OCPD diagnosis ratings decreased over time in individuals with OCD and consists of a mix of enduring and episodic symptom criteria. It suggests the need for a refinement of OCPD diagnostic criteria and future research on symptom stability of OCPD across different diagnostic groups.

  PublisherDOI

• Gauging Public Perception of Neurosurgery for Obsessive-Compulsive Disorder:A Qualitative and Descriptive Analysis of Online Forums (Preprint)

  2025-03-27

  preprintOpen access

  <sec> <title>BACKGROUND</title> Psychiatric neurosurgery, including deep brain stimulation (DBS) and neuroablative procedures, has shown significant promise in treating severe, intractable Obsessive-Compulsive Disorder (OCD). The emergence of innovative neurostimulation techniques and neuroablation targets has catalyzed discussions in mainstream media. Online chat forums such as Reddit and Quora serve as particularly valuable resources for gauging public perception of medical interventions and technologies, making them crucial for researchers and clinicians in understanding how these procedures are viewed by the public. </sec> <sec> <title>OBJECTIVE</title> This study aims to evaluate public perceptions of psychiatric neurosurgery for OCD, as expressed in online chat forums, and to identify prevalent discussion topics and misinformation. </sec> <sec> <title>METHODS</title> We conducted a qualitative thematic analysis of 254 online posts discussing psychiatric neurosurgery for OCD, posted between 2008 and 2020 on popular forums. Three independent reviewers coded the posts, determining key discussion topics, characteristics, and misinformation. The data were analyzed using Applied Thematic Analysis (ATA) to identify structural and interpretive components and statistical analyses to quantify post characteristics. </sec> <sec> <title>RESULTS</title> There has been a burgeoning interest in psychiatric neurosurgery for OCD on these forums since 2008, with analyzed posts amassing over 25,000 cumulative online views. Thematic analysis identified three primary discussion topics: the efficacy of neurosurgical procedures, the existence of these procedures as treatment options, and their associated risks and benefits. Notably, statistical analysis found that 30.6% of posts contained misinformation, with a significantly higher rate of inaccuracies in posts expressing negative views of surgery compared to those expressing neutral or positive views (p=0.0079). Posts often began with users seeking information or sharing personal experiences, highlighting a gap between public perception and clinical evidence. </sec> <sec> <title>CONCLUSIONS</title> Our findings reveal significant interest and engagement in online discussions about psychiatric neurosurgery for OCD, accompanied by substantial misinformation. These insights underscore the need for targeted educational interventions to bridge the gap between public perception and clinical evidence. Addressing misinformation and enhancing public understanding could improve patient outcomes and referral patterns for those considering psychiatric neurosurgery. This study provides valuable data for clinicians aiming to better comprehend and navigate public concerns and misconceptions in this rapidly evolving field. </sec>

  PublisherOA PDFDOI

• Examining relationships among NODDI indices of white matter structure in prefrontal cortical-thalamic-striatal circuitry and OCD symptomatology

  Translational Psychiatry · 2024-10-02 · 1 citations

  articleOpen access

  Obsessive-compulsive disorder is a psychiatric disorder characterized by intrusive thoughts and repetitive behaviors. There are two prominent features: Harm Avoidance (HA) and Incompleteness (INC). Previous resting-state studies reported abnormally elevated connectivity between prefrontal cortical (PFC) and subcortical regions (thalamus, striatum) in OCD participants. Yet, little is known about the white matter (WM) structural abnormalities in these connections. Using brain parcellation and segmentation, whole brain tractography, and Neurite Orientation Dispersion and Density Imaging (NODDI), we aimed to characterize WM structural abnormalities in OCD vs. healthy controls and determine the extent to which NODDI indices of these connections were associated with subthreshold-threshold HA, INC and overall OCD symptom severity across all participants. Four PFC regions were segmented: ventral medial (vmPFC), ventrolateral (vlPFC), dorsomedial (dmPFC), and dorsolateral (dlPFC). NODDI Neurite Density (NDI) and Orientation Dispersion (ODI) indices of WM structure were extracted from connections between these PFC regions and the thalamus (42 OCD, 44 healthy controls, mean age[SD] = 23.65[4.25]y, 63.9% female) and striatum (38 OCD, 41 healthy controls, mean age[SD] = 23.59[4.27]y, 64.5% female). Multivariate analyses of covariance revealed no between-group differences in these indices. Multivariate regression models revealed that greater NDI in vmPFC-thalamus, greater NDI and ODI in vmPFC-striatum, and greater NDI in dmPFC-thalamus connections were associated with greater INC severity (Q ≤ 0.032). These findings highlight the utility of NODDI in the examination of WM structure in OCD, provide valuable insights into specific WM alterations underlying dimensional INC, and can facilitate the development of customized treatments for OCD individuals with treatment-resistant symptoms.

  PublisherOA PDFDOI

• Obsessive-Compulsive Personality Disorder Symptom Stability in Individuals with Obsessive Compulsive Disorder over Six Years of Prospective Follow-up

  2024-06-08

  preprint

  Background: Obsessive-compulsive disorder (OCD) commonly co-occurs with personality disorders, particularly obsessive-compulsive personality disorder (OCPD). Recent research suggests that personality disorders, especially OCPD, might not be as stable as once thought. Thus, the current study aims to investigate the longitudinal stability of OCPD diagnosis and individual symptom criteria in individuals with OCD. Methods: 107 participants with a primary diagnosis of OCD were included in the study. Cochran’s Q tests were conducted to assess whether there were significant changes in the proportions of individuals endorsing an OCPD diagnosis and each of the eight OCPD symptom criteria across three time points over six years. Results: Although the percentage of participants diagnosed with OCPD remained consistent across the study, closer inspection of the data suggested diagnostic instability, with participants moving in and out of OCPD diagnosis. Five individual criteria (detail-oriented, reluctance to delegate, inflexible, overconscientious, and scrupulous, excessive work devotion, and miserly spending style) were shown to be stable and the other three (perfectionism, rigidity and stubbornness, and hoarding) were unstable. Conclusion: OCPD diagnosis is not stable in individuals with OCD and consists of a mix of enduring and episodic symptom criteria. It suggests the need for a potential refinement of OCPD diagnostic criteria and future research on symptom stability of OCPD across different diagnostic groups.

  PublisherDOI

Recent grants

• Longitudinal Follow-Up Study of Obsessive Compulsive Disorder

  NIH · $6.3M · 2001–2017

• Physiology and information processing of the OCD circuit

  NIH · $51.3M · 2015–2027

• NIH Grant P50MH086400

  NIH · $20.5M · 2015

Frequent coauthors

• Benjamin D. Greenberg

  Providence VA Medical Center

  333 shared

• Jonathan A. Eisen

  265 shared

• Maria C. Mancebo

  Providence College

  195 shared

• Nicole McLaughlin

  Allen Institute for Brain Science

  157 shared

• Lawrence H. Price

  106 shared

• Katharine A. Phillips

  104 shared

• Sarah L. Garnaat

  Dartmouth College

  96 shared

• Christina L. Boisseau

  92 shared

Education

• Other

  Brown Medical School

  1977

• M.D.

  Brown Medical School

  1977