Dr. Haghighi's research specialty is in medical epigenetics with applications to traumatic brain Injury (TBI), depression, and suicidal behavior. These epigenetic studies involve how genes are differentially transcribed and regulated, within human clinical and postmortem brain samples, providing a snapshot of potential transcriptional regulatory abnormalities associated with disease neuropathology. Dr. Haghighi's clinical studies show how environmental exposure affects the epigenome. Specifically, in her studies involving traumatic brain injury, she investigates how response to repeated blast-exposure induces long-term transcriptional regulatory changes resulting in symptoms of sleep disturbances, anxiety, cognitive deficits and depression and PTSD. Additionally, she investigates how the role of stress, specifically chronic stress, induces epigenetic changes associated with depression and suicide in the Veteran population.