A previous post explored some of the risk factors for prolonged symptoms following concussion. A risk factor is a thing (a variable) that increases the chances that another thing will happen (an outcome). For example, playing football is a risk factor for concussion because football players tend to have more hits to the head then people who do not play football.
The previous post showed that patients who reported emotional symptoms (sadness, feeling emotional, nervousness, or irritability) following concussion were more likely to have longer recovery times than patients with concussion but without emotional symptoms. In other words, having emotional symptoms with concussion was a risk factor for prolonged concussion symptoms.
This post will discuss a recent study that looked at risk factors for developing depressive symptoms following concussion.
To be diagnosed with depression, a patient must have certain symptoms daily, or nearly every day, for at least two weeks. The study below used a questionnaire to identify depressive symptoms among patients with concussion. In this case, depressive symptoms can be defined as symptoms that are common among patients with a depression diagnosis.
A study by Dr. Stazyk and colleagues collected information about depression and other clinical features from 92 children (aged 7-18 years) with concussion.1 Depressive symptoms were found in 20 (22%) of those patients. In a community sample (defined as a group of individuals selected randomly from a community), depressive symptoms were present in 8% to 11% of individuals. So, the patients with concussion in this study were at least twice as likely as a random group of individuals to have depressive symptoms.
Comparing the patients with and without depressive symptoms, those with depressive symptoms were more likely (1) to report more overall concussion symptoms and longer recovery and (2) to be hospitalized for their concussion injuries.
When we look at this study and the study presented in the previous post, the results seem to overlap: emotional symptoms are a risk factor for prolonged concussion symptoms, while severe and prolonged concussion symptoms appear to be a risk factor for depression. How should this be interpreted? It is possible that severe concussions are more likely to cause severe symptoms that include sadness, feeling emotional, nervousness, and irritability. This would also explain why patients with depressive symptoms were more likely to be hospitalized for concussion. Alternatively, it is possible that some patients are somehow more susceptible to both depression and prolonged concussion recovery. For example, maybe there be a gene (or genes) that increase the risk of both.
Future research should study how best to treat depression and other emotional symptoms following concussion. Some experts recommend treating depression related to concussion the same as treating depression that is not related to concussion.2 But not all experts agree. More research is needed.
- Stazyk K, DeMatteo C, Moll S, Missiuna C. Depression in youth recovering from concussion: Correlates and predictors. Brain Inj. 2017;31(5):631-638.
- Silverberg ND, Panenka WJ. Antidepressants for depression after concussion and traumatic brain injury are still best practice. BMC Psychiatry. 2019;19:100.