Aurora, Colo. – September 19, 2026 -- A new study from the University of Colorado Anschutz Marcus Institute for Brain Health finds that irritability following chronic mild traumatic brain injury (mTBI) in military veterans stems from a combination of PTSD symptoms, chronic pain and difficulty understanding speech in noisy environments, not a single psychological cause.
Study of 124 veterans links irritability to three distinct factors
Published in the Journal of Neuropsychiatry and Clinical Neurosciences, the research examined 124 military veterans, including 61 with chronic mTBI and 63 without any history of brain injury. Participants underwent standardized assessments measuring irritability, PTSD symptoms, chronic pain, balance and auditory processing, including speech-in-noise comprehension.
Veterans with chronic mTBI show higher irritability and impaired sensory processing
Veterans with chronic mTBI reported higher irritability, more severe PTSD symptoms, greater chronic pain, worse balance and increased difficulty understanding speech in noisy settings compared with veterans without brain injury. PTSD symptoms showed the strongest association with irritability, followed by chronic pain.
Speech-in-noise difficulty independently contributes to emotional overload
The study is among the first to identify that difficulty following conversations in noisy environments independently contributes to irritability after chronic mTBI. "When the brain must work harder to understand speech in noisy environments, it increases mental effort and fatigue. Over time, that can reduce stress tolerance and contribute to emotional overload and irritability," said Jeffrey Hebert, PhD, PT, the study's lead investigator and director of research for the Marcus Institute for Brain Health.
Findings point to integrated screening for PTSD, pain and hearing deficits
Hebert said the results indicate that everyday environments such as restaurants, social gatherings and crowded public spaces may be especially challenging for individuals living with chronic mTBI. He added that effective care may require addressing PTSD symptoms, chronic pain and sensory processing difficulties together rather than in isolation. Future research will examine whether improving functional hearing and sensory processing reduces irritability and enhances quality of life after concussion.