Traumatic brain injuries (TBIs) are a significant public health issue, leading to various cognitive, physical, and emotional challenges. Concussion in sports has elevated this topic in public awareness. However, a relatively lesser discussed topic related to TBI is the concerning association between TBIs and the onset of mood disorders, such as major depression and bipolar disorder.
Studies indicate that individuals who have experienced a head injury face a substantially increased risk of developing psychiatric conditions, with some disorders seeing an increase of up to 400% (Orlovska et al., 2014). It is my hope that this article will contribute to raising awareness on the problematic relationship between TBIs and mood disorders, particularly bipolar disorder, which I have chosen to emphasize because it is also an underappreciated diagnosis, associated with a great deal of stigma, and because we frequently see bipolar disorder manifested in our clients who present with issues related to TBI.
Increased Risk of Mood Disorders Following Brain Injury
According to a study published in The American Journal of Psychiatry, individuals who sustain a TBI are 439% more likely to develop a psychiatric disorder compared to those without such an injury (Orlovska et al., 2014). This significant figure underscores the profound impact head injuries can have on mental health.
While major depressive disorder and anxiety disorders are the most common psychiatric disorders after TBI, with prevalence ranges of 13% to 53% and 11% to 70% respectively (Practical Neurology, 2023), bipolar disorder, though less frequently reported, presents unique challenges. A systematic review highlighted that mania, a hallmark of bipolar disorder, while relatively less common following TBI than depression and anxiety, can be a debilitating psychiatric occurrence following TBI (Neuropsychiatry Online, 2022). Symptoms of bipolar disorder—including episodes of extreme mood swings from depressive lows to manic highs—may manifest as early as the first year post-injury or as late as 15 years afterward (Jorge et al., 2014). These delayed manifestations emphasize the complexity of TBI-related psychiatric outcomes.
Mechanisms Behind the Increased Risk
The connection between TBI and mood disorders is multifaceted, involving both biological and psychological factors. TBIs can lead to structural and functional changes in the brain, particularly in regions essential for emotional regulation, such as the frontal lobe and limbic system (Jorge et al., 2014). Disruptions in neural pathways and neurotransmitter imbalances, especially concerning dopamine and serotonin, can predispose individuals to mood disorders.
Inflammatory processes initiated by brain injuries may also contribute. Neuroinflammation can exacerbate damage to brain tissue, leading to long-term emotional dysregulation and an increased vulnerability to psychiatric conditions (Mannix et al., 2013). Additionally, hormonal changes, such as dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, has been suggested to potentially heighten susceptibility to depression and mania.
The "Chicken and Egg" of TBI and psychiatric disorders
A reasonable misconception in studying TBI-related psychiatric disorders is that individuals with TBI had undiagnosed psychiatric conditions or a predisposition to mood disorders that made them more prone to injury (rather than the injury directly causing or contributing to the disorder). Research appears to support the latter. Studies have controlled for pre-existing conditions and found a clear causal relationship between TBIs and subsequent psychiatric diagnoses. While pre-existing vulnerabilities may amplify the risk, and mental health issue can contribute to risky behaviors that lead to head injury, it is safe to say that for many individuals who suffer from psychiatric diagnoses following TBI, the injury itself likely served as a significant and independent trigger for mood disorders.
Early Detection and Intervention
Recognizing the heightened risk of psychiatric disorders following a TBI is crucial for timely intervention. Symptoms of mood disorders, including bipolar disorder, can significantly impair an individual’s quality of life if left untreated. Warning signs might include:
Depressive symptoms: Persistent sadness, fatigue, feelings of hopelessness, and changes in sleep or appetite.
Manic symptoms: Periods of unusually high energy, irritability, impulsivity, reduced need for sleep, and apparently changes in personality.
Individuals who have sustained a TBI should be monitored over an extended period of time, particularly within the first year post-injury, and remain vigilant for psychiatric symptoms even years later. For these individuals, early interventions, such as psychotherapy, mood-stabilizing medications, and supportive care, can mitigate the impact of mood disorders on recovery and daily life.
So do we treat the Brain or the Psychiatric Condition?
Unfortunately, when individuals who have undergone TBI, seek help with psychiatric issues they typically are treated for one or the other (i.e., they are treated for "just" the mental health issues, typically by mental health providers, or "just" the brain issue (e.g., by neurorehabilitation providers). However, evidence suggests that neurorehabilitation, combined with psychiatric care, can improve psychiatric outcomes in individuals with traumatic brain injury (TBI). A systematic review of randomized controlled trials (RCTs) indicated that multidisciplinary rehabilitation could enhance participation and reduce mental health symptoms in adults with moderate to severe TBI (Brasure et al., 2013). Indeed, this is the emphasis of our own practice, which combines discplines to simultaneously optimize brain function while addressing psychiatric components of the client's condition, wherein the care approach is cohesive and synergistic. We believe that this approach is the future of both psychiatric care and neurology/neurorehabilitation.
Summary
Traumatic brain injuries not only pose immediate physical challenges but also significantly increase the risk of long-term psychiatric conditions, including bipolar disorder. Research underscores the importance of recognizing TBIs as a key factor in mental health diagnoses. By fostering awareness and prioritizing early detection, healthcare professionals and caregivers can provide effective support for individuals navigating the complex interplay between brain injury and mental health.
About the Author: David George is a multiple-board certified founder and lead clinician at Neuregen Integrative Psychiatry and Neurologic Health Center in Scottsdale, Arizona. Neuregen offers a range of diagnostic and therapeutic services for individuals suffering from persistent symptoms following brain injury, including concussion (mTBI). This includes psychiatry, neuro- and physiotherapy, interventional procedures for polytrauma, regenerative medicine, psychedelic medicine, and complementary and alternative therapies.
References
Jorge, R. E., & Starkstein, S. E. (2014). Pathophysiologic aspects of major depressive disorder following traumatic brain injury. The Journal of Head Trauma Rehabilitation, 19(3), 113-124. https://doi.org/10.1097/00001199-200405000-00004
Mannix, R., Meehan, W. P., & Pascual-Leone, A. (2013). Sports-related concussions and neurodegeneration: A multifaceted clinical challenge. Neuron, 80(5), 1230-1242. https://doi.org/10.1016/j.neuron.2013.10.034
Orlovska, S., Pedersen, M. S., Benros, M. E., Fenger-Grøn, M., Nordentoft, M., Erlangsen, A., & Gasse, C. (2014). Head injury as risk factor for psychiatric disorders: A nationwide register-based follow-up study of 113,906 persons with head injury. The American Journal of Psychiatry, 171(4), 463-469. https://doi.org/10.1176/appi.ajp.2013.13020190
Practical Neurology. (2023). Mood Disorders Following Traumatic Brain Injury. Retrieved from https://practicalneurology.com/articles/2023-apr/mood-disorders-following-traumatic-brain-injury
Neuropsychiatry Online. (2022). Mania Following Traumatic Brain Injury: A Systematic Review. Retrieved from https://psychiatryonline.org/doi/10.1176/appi.neuropsych.20220105
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