CU Anschutz research suggests post-concussion irritability reflects combined effects of brain function changes, emotional health and difficulty understanding speech in noisy environments rather than a single psychological cause
AURORA, Colo., Sept. 17, 2026 / — New research from the CU Anschutz Marcus Institute for Brain Health shows that irritability is strongly associated with post-traumatic stress disorder (PTSD) symptoms, chronic pain and difficulty understanding speech in noisy environments among military veterans with chronic mild traumatic brain injury (mTBI), or concussion.
Published today in the Journal of Neuropsychiatry and Clinical Neurosciences, the study suggests that post-concussion irritability may reflect a combination of changes in brain function, emotional health and sensory processing rather than a single psychological cause.
Irritability is one of the most reported long-term symptoms after concussion, particularly in veterans with chronic mTBI. It can significantly disrupt work, relationships and social functioning.
“Our findings suggest irritability years after multipleconcussions is not simply a psychologically-driven emotional reaction,” said the study’s lead investigator Jeffrey Hebert, PhD, PT, associate professor at the CU Anschutz School of Medicine and director of research for the University of Colorado Anschutz Marcus Institute for Brain Health. “It reflects difficulties managing both psychological and sensory system factors that can persist for years after injury.”
The study included 124 military veterans, consisting of 61 with chronic mTBI and 63 without any history of brain injury. Participants completed standardized assessments measuring irritability, PTSD symptoms, chronic pain, balance and auditory processing, including speech in noise comprehension.
Veterans with chronic mTBI reported higher levels of irritability, more severe PTSD symptoms, greater chronic pain, worse balance and increased difficulty understanding speech in noisy settings compared with those without brain injury.
Researchers found that PTSD symptoms had the strongest association with irritability, followed by chronic pain. Difficulty understanding speech in challenging listening environments also contributed independently, suggesting that sensory strain plays a role in emotional regulation.
The findings are among the first to show that difficulty following conversations in noisy environments may independently contribute 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 Hebert.
The results also highlight how everyday environments such as restaurants, social gatherings and crowded public spaces may be especially challenging for individuals living with chronic mTBI.
Overall, the study emphasizes that irritability after concussion likely involves multiple interacting systems in the brain and body.
“This work shows the issue cannot be understood through a single lens. Effective care may require addressing PTSD symptoms, chronic pain and sensory processing difficulties together rather than in isolation,” said Hebert.
Future research will explore whether improving functional hearing and sensory processing could reduce irritability and enhance quality of life after concussion.
Key Findings
- Irritability after concussion was most strongly linked to PTSD symptoms and chronic pain
- Difficulty understanding speech in noisy environments also contributed to irritability
- Veterans with chronic mTBI experienced higher emotional, physical, and sensory symptoms
- Findings support more integrated screening and treatment approaches
Why the Research Matters
Long term symptoms after concussion are common in military veterans and can affect daily life, including work and relationships. Irritability is one of the most disruptive symptoms, but is often viewed only as behavioral or psychological. This study suggests it may instead reflect changes in brain function, sensory processing, and emotional regulation, supporting more comprehensive approaches to care.
Clinical Implications
Clinicians treating patients with chronic mTBI may improve outcomes by screening for PTSD symptoms, chronic pain, and difficulty understanding speech in noisy environments when irritability is present.
About Mild Traumatic Brain Injury (mTBI)
Mild traumatic brain injury (mTBI), commonly called concussion, can result from blasts, falls, sports injuries, or vehicle accidents. Although considered “mild,” symptoms may persist long after injury and can include headaches, fatigue, memory problems, sleep disruption, mood changes, and sensitivity to sensory stimuli.
About the Study
The study examined relationships between irritability, PTSD symptoms, chronic pain, balance and auditory processing, including difficulty understanding speech in noisy environments, in military veterans with and without chronic mild traumatic brain injury.
About the University of Colorado Anschutz
The University of Colorado Anschutz is a world-class academic medical campus leading transformative advances in science, medicine, education and patient care. The campus includes the University of Colorado’s health professional schools, more than 60 centers and institutes, and two nationally ranked independent hospitals – UCHealth University of Colorado Hospital and Children’s Hospital Colorado – which see nearly three million adult and pediatric patient visits each year. Innovative, interconnected and highly collaborative, CU Anschutz delivers life-changing treatments, exceptional patient care and top-tier professional training. The campus conducts world-renowned research supported by $890 million in funding, including $762 million in sponsored awards and $128 million in philanthropic gifts for research.
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SOURCE University of Colorado Anschutz
