Symptoms include intrusive memories, distressing dreams, flashbacks, psychological distress, and physiological adverse reactions.15 Reported prevalence of PTSD symptoms following TBI varies widely from 6% to 39% across both military and civilian populations.3,12,16 Headache may hinder recovery from the cognitive and behavioral consequences of TBI.6 Patients frequently have both PTH and PTSD symptoms,3,6,12,16 but the relationship between the symptoms is less defined. The gene discussed is PTH; the disease is post-traumatic stress disorder.