Faculty Profile: Benjamin Greenberg, MD, PHD

Benjamin Greenberg
Benjamin Greenberg, MD, PHD
Associate Professor of Psychiatry & Human Behavior
Psychiatry & Human Behavior
Work: +1 401-455-6602
My focus is the pathophysiology and treatment of obsessive-compulsive disorder (OCD). I use brain stimulation, cognitive probes, and a variety of neuroimaging techniques to probe brain circuits implicated in symptom expression and in the response to treatment, and to reveal more about the neuroanatomical underpinnings of OCD symptoms.



Research Description

My focus is the pathophysiology and treatment of obsessive-compulsive disorder (OCD). I use brain stimulation, cognitive probes, and neuroimaging to probe brain circuits implicated in symptom expression and in the response to treatment. Current neurobiological models propose that hyperactivity within circuits linking the cerebral cortex, basal ganglia, and thalamus is crucial to OCD symptoms. Our primary study attempts to reduce symptoms in patients with severe and treatment-refractory illness with electrical stimulation within these circuits, called deep brain stimulation (DBS). We also do PET imaging of regional brain function to determine if symptom improvement after DBS is associated with reductions in activity in these areas. Cognitive probes, some standard and some under develpment, are used to determine how information processing changes in the same brain circuits after DBS, and after stimulation of prefrontal cortex, using transcranial magnetic stimulation.

Finally, a parallel study uses diffusion tensor MRI to develop detailed maps of brain fibers, to determine how brain connectivity changes after gamma knife capsulotomy, a neurosurgical treatment for people with intractable OCD. In capsulotomy, circumscribed lesions are made in white matter tracts connecting the thalamus to orbitofrontal cortex. Diffusion tensor MRI, capable of showing anatomical changes in these pathways at a distance from the primary lesion, may help define the anatomical changes most associated with therapeutic benefit after capsulotomy, and thus reveal more about the neuroanatomical underpinnings of OCD symptoms.

Grants and Awards

Best Review Article of the Year, CNS Spectrums, 2003
Research Mentor Award, Brown University Department of Psychiatry and Human Behavior, 2001
Early Career Award, EEG and Clinical Neuroscience Society (ECNS), 2001
APA/SmithKline Beecham Young Faculty Award, Hon. Mention, 2000
Young Investigator Award, American Neuropsychiatric Association, 1995
DISTA Fellowship, Society of Biological Psychiatry, 1991



American College of Neuropsychopharmacology, Associate Member, 1999
Obsessive-Compulsive Foundation, 1998
Founding member, International Society for Transcranial Stimulation, 1997
American Neuropsychiatric Association, 1997
American Society of Clinical Psychopharmacology, 1996-1999
Society of Biological Psychiatry, 1992
American Psychiatric Association, Maryland Psychiatric Society, 1992

Funded Research

Investigator Award (S. Rasmussen PI) 2/2/2001 – 6/30/2006 5%
Medtronic, Inc. $100,000
Deep Brain Stimulation for Intractable Obsessive Compulsive Disorder
Role: Principal Researcher
Efficacy and safety of deep brain stimulation of the internal capsule in intractable OCD

Investigator Award (Greenberg) 6/1/2001 - 6/30/2005 5%
Charles A. Dana Foundation $35,875 (no cost extension)
Diffusion Tensor MRI Mapping of How Brain Fiber Tracts Change After Gamma Knife Capsulotomy for Intractable Obsessive Compulsive Disorder
The main hypothesis is that reduction on thalamo-orbitofrontal cortex fibers on diffusion tensor imaging after gamma capsulotomy will be associated with symptomatic improvement.

RO-1 MH50214 (Nestadt) 6/1/2001 - 5/31/2006 15%
National Institute of Mental Health (NIMH) $97,081 (sub only)
Collaborative OCD Genetics Study
Role: Lead Site Investigator
This study aims to refine the OCD phenotype by identifying homogeneous clinical subtypes and conducts a systematic genome wide scan to 1) refine the OCD phenotype and 2) to identify potential chromosomal regions linked to OCD susceptibility genes and to initiate studies to narrow potentially relevant chromosomal loci.

Award (Greenberg) 11/1/2004 - 10/31/2005 5%
Collaboration for Translational Brain Research, Brown Medical School $35,000 (Direct)
Behavioral Aspects of Deep Brain Stimulation
This award supports systematic data collection on psychiatric and behavioral effects of deep brain stimulation in movement disorder patients.

RO-1 (S. Haber, PI) 12/1/2005 – 11/31/2010 12.5%
NIMH/ National Institute on Drug Abuse (NIDA) $55,922 (Year 1 Direct Costs)
Neural Networks in OCD
Role: Principal Site Researcher
This translational study aims to understand the mechanisms of therapeutic action of deep brain stimulation in OCD using neuroimaging in patients, neuroanatomy in primates, and electrophysiology in rodents.


RO-1 B.D. Greenberg, PI
Controlled Trial of Deep Brain Stimulation for Obsessive-Compulsive Disorder
This multisite clinical study will use a controlled parallel design to test the efficacy and safety of DBS in highly resistant OCD, together with PET neuroimaging, to test hypotheses about regional brain metabolic predictors of response and correlates of therapeutic effects in this severely affected patient group.