This paper focuses on the effects of repeated head trauma in athletes and how these repetitive blows to the head are causing a range of mental health problems. The primary focus, in terms of problems addressed, is chronic traumatic encephalopathy (often referred to as CTE) in the population of athletes, especially those participating in contact and combat sports. The disorders covered are caused by the cumulative effects of both concussive and sub-concussive blows to the head over a period of time.