A concussion is often followed by psychological disturbances such as mood fluctuation which often result in personality changes. Some of these changes include increased irritability, anxiety, depression, impulsivity, social disinhibition, and impaired perception of emotional stimuli. Such fluctuations are often reported based on the patient’s own evaluation of these changes as well as other people’s judgement, such as relatives and friends, who also observe similar personality changes in their loved ones after their injury. Many of these symptoms subside as other symptoms improve; personality changes are typically linked to the experience of other symptoms after the injury.

The Diagnostic and Statistical Manual of Mental Disorders (DSM) proposed five major subtypes of personality changes associated with traumatic brain injuries which are: affective lability (rapid mood changes), aggression, disinhibition, apathy, and paranoia. Even in children such changes are observed. For instance, a study found that 6 months after experiencing a traumatic brain injury, 22% of children experienced personality changes but it dropped to 13% one year after the injury.

Which factors contribute to these changes?

• Psychosocial factors: One of the most prominent predictors of personality changes is psychosocial adjustment. Stress levels are associated with greater probability of experiencing personality changes. Depression and anxiety levels also play a similar role as stress and can also lead to increased aggression. Additionally, changes in social roles contribute to the severity of the changes and to the depression and anxiety experienced. For example, vocational loss or requiring increased support can lead to pressure, financial hardship, and depression, which can exacerbate personality changes.

1. Severity of injury: Likelihood of experiencing personality changes increase as the severity of the brain injury increases. The recovery period until the patient returns to their normal self also correlates with the severity of the injury experienced.

1. General cognitive impairment: These include difficulty concentrating, making decisions, and mental-intellectual deficits. Research has shown that judgement of personality changes increase as these cognitive deficits increase and become more severe.

1. Location of injury: The orbitofrontal cortex located in the frontal lobe has a role in executive functions and controlling impulsivity. Traumatic brain injuries that lead to orbitofrontal damage can result in reduced social responding, increased impulsivity, and disinhibition. 

• Type of injury: In a study conducted on US veterans who experienced mild traumatic brain injuries, those whose injuries were from blast force (pressure waves hitting the brain such as after an explosion) experienced more anger, frustration, toughness, and more neuroticism compared to those whose injuries were of the blunt type (such as being hit on the head).

Although all changes discussed so far have been negative, some studies reported positive outcomes as well. For instance, increased emotional closeness to people can also occur following a concussion especially towards parents, partners, and caretakers. Negative changes can be challenging to deal with, but education and awareness around this issue helps concussion survivors feel understood and supported on their recovery journeys.

Written by Lea Farah

References

Max, J. E., Levin, H. S., Schachar, R. J., Landis, J., Saunders, A. E., Ewing-Cobbs, L., Chapman, S. B., & Dennis, M. (2006). Predictors of personality change due to traumatic brain injury in children and adolescents six to twenty-four months after injury. The Journal of Neuropsychiatry and Clinical Neurosciences, 18(1), 21-32. https://doi.org/10.1176/appi.neuropsych.18.1.21

Mendez, M. F., Owens, E. M., Jimenez, E. E., Peppers, D., & Licht, E. A. (2013). Changes in personality after mild traumatic brain injury from primary blast vs. blunt forces. Brain Injury, 27(1), 10-18. https://doi.org/10.3109/02699052.2012.722252

Weddell, R. A., & Leggett, J. A. (2006). Factors triggering relatives’ judgements of personality change after traumatic brain injury. Brain Injury, 20(12), 1221-1234. https://doi.org/10.1080/02699050601049783