Suicidality is a significant outcome of TBI in military and civilian community research samples. There have been different studies that have found correlations between TBI and suicidal ideation and behaviors. This includes having studies that control for risk factors, including depression, PTSD, and TBI symptom severity. Different studies have shown that servicemembers who have TBI are at risk of completing suicide or have suicidal ideation in comparison to the general population. In addition, depression and PTSD are also risk factors for suicide. On the other hand, individuals who have played American football have a lower risk of committing suicide than the general population.