Post-concussion irritability linked to PTSD, chronic pain, and auditory difficulties

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. It reflects difficulties managing both psychological and sensory system factors that can persist for years after injury."

Jeffrey Hebert, PhD, PT, study's lead investigator, associate professor, CU Anschutz School of Medicine and director of research, University of Colorado Anschutz Marcus Institute for Brain Health

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.