Depression and Brain Injuries

Feelings of sadness, emptiness or hopelessness. Disinterest in daily activities. Fatigue or loss of energy. These are just some of the symptoms of one of the most prevalent mental health disorders, depression, which affects approximately 1 in 10 people. However, when the person suffering from depression has a brain injury, these details may change.


There are two main differences for diagnosing depression in patients with and without brain injuries. The first difference is that symptoms associated with depression may also be associated with brain injury. This makes it difficult to determine the cause of the symptoms and may result in an incorrect diagnosis of depression in patients with brain injuries.

The second difference is that the standard symptoms of depression may not show in those with brain injury. For example, depression in those without brain injuries is most characterized by feelings of sadness, while in those with brain injuries it is most characterized by irritability, anger and aggression3. This means that the individual suffering from depression may not recognize what they have.


Another change is the likelihood (or prevalence) of a person with a brain injury developing depression. One study indicates that 26% of patients with brain injuries are diagnosed with depression at initial assessment and 18-30% are diagnosed six months after injury, with lifetime prevalence being 18.5%. A second study indicates that 27% of patients are diagnosed with depression 3-6 months after injury, 32% are diagnosed 6-12 months after injury, and 33% 12 months after injury, with lifetime prevalence being 30%. Despite the range in statistics, it is clear that studies have found the prevalence is significantly higher than for patients without brain injuries (10%).


Brain injuries also introduce several additional factors that increase the likelihood of developing depression, such as:

  • Physical Changes: damage to areas of the brain that control emotions or changes in levels of neurotransmitters; and
  • Emotional Response: struggling to adjust to life with a disability and changes in familial and societal roles.


There are some significant differences in the presentation of depression in individuals with and without brain injuries. Brain injuries can cause depression to present with unique symptoms and increase the overall likelihood of developing depression. As such, it is important to take note of all changes that present and to discuss them with your doctor.


American Psychiatric Association (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.).

Agency for Healthcare Research and Quality (2011). Depression After Brain Injury. Retrieved from

Dilley, M. and Avent, C. (2011). Long-Term Neuropsychiatric Disorders after Traumatic Brain Injury. Psychiatric Disorders – Worldwide Advances. Retrieved from

Holsinger, T., Steffens, D.C., Phillips, C., Helms, M.J., Havlik, R.J., Breitner, J.C.S., Guralnik, J.M. and Plassman, B.L. (2002). Head Injury in Early Adulthood and the Lifetime Risk of Depression. Arch Gen Psychiatry, 59. Retrieved from

Agency for Healthcare Research and Quality (2011). New Comparative Effectiveness Review Released on Traumatic Brain Injury and Depression. Retrieved from

Fann, J and Hart, T. Depression After Traumatic Brain Injury. Retrieved from


Written By: Anna Maine

Anna Maine graduated from the University of Alberta with a double major in English and Psychology. She currently works as an Office Administrator for an engineering  company in Edmonton.