Brendon Nacewicz, M.D., Ph.D.

Assistant Professor (Tenure Track)

Neurochemical, structural and circuit-based investigations into excessive fear generalization and consequent depersonalization in psychiatric disease

Wisconsin Psychiatric Institute and Clinics
6001 Research Park Blvd

Nacewicz Lab
UW Health
Provider Profile

Dr. Nacewicz is a Physician Scientist specializing in Post-Traumatic Stress Disorder (PTSD) and anxiety disorders treatable by exposure therapy. He provides medication management for PTSD and the common comorbid conditions Specific Phobias, Obsessive Compulsive Disorder (OCD), and other compulsive behaviors in his adult psychiatry practice. He also completed formal training and is certified in facilitated exposure therapy with Eye-Movement Desensitization and Reprocessing (EMDR) and continues a limited psychotherapy practice.

His PhD is in the neuroscience of autism spectrum disorders, uncovering biomarkers and neurochemical signatures of chronic overload of the amygdala, a center of fear and emotional processing, that paralleled impairments in reciprocal social behavior. Collaborative postgraduate work expanded these findings to consequences of abuse, neglect and poverty. Combined with his clinical experience treating post-traumatic stress, this expanded his focus to general mechanisms by which intense fear and stress cause “depersonalization”, the inability to feel connected with others and take their perspective. A major interest is how feelings of warmth and social connectedness recovers as people extinguish fear memories and recover from acute stress. His current research employs Magnetic Resonance Spectroscopy (MRS) to directly measure neurotransmitters in specific emotional and cognitive centers of the brain to capture mechanisms of fear generalization and recovery. He has adapted MRS for very small regions and for high-temporal resolution functional measurements (ht-fMRS) in human emotional centers, examining neurotransmitter imbalances in amygdala during typical and autistic development, during direct neuromodulation (Transcranial Magnetic Stimulation, TMS) and ultimately will explore effects of medications and psychotherapy. To better understand the origins of the neurotransmitter changes, he is combining MRS with functional genetic manipulations, ex-vivo metabolomics of cerebrospinal fluid, and expansion microscopy of nonhuman primate brain regions mediating fear and social behavior. These important studies will identify key circuits and neurochemicals that could one day allow non-invasive MRS or cerebrospinal fluid metabolomics to inform treatment choice, dosing and track efficacy of emerging treatments.


  • Exposure Therapy (EMDR)
  • PTSD
  • Phobias
  • Anxiety Disorders
  • Adults with Autism and Developmental Disorders (Limited Practice)