A multinational team of researchers has determined that people who have sustained concussions are more likely to be diagnosed with post-traumatic stress disorder (PTSD) than with post-concussion syndrome (PCS) several months after injury. Concussions are a form of relatively minor traumatic brain injury that occur when a person\u2019s head hits an object or when an object in motion hits a person\u2019s head. In the aftermath of such an injury, some individuals develop a condition called post-concussion syndrome, which has some overlying symptoms with PTSD. Concussions and PCS Concussions produce their damaging effects by altering various aspects of brain function. In relatively mild cases, potential symptoms of this form of brain injury include headaches, muddled thinking or confusion, nausea, vomiting, short-term memory loss, short-term loss of consciousness and unusual sleepiness or difficulty waking up after falling asleep. Potential symptoms of more severe forms of concussion include recurring episodes of vomiting, lasting mental disorientation, convulsions, loss of control over body balance, unusually weak muscles, uneven eye pupils and longer stretches of unconsciousness that may include a coma (i.e. a prolonged period of unresponsiveness to outside stimuli). Depending on the extent of the brain damage present in the individual, full recovery from a concussion may take anywhere from a few days to several months. In relatively rare cases, symptoms of the condition never fully resolve. Doctors sometimes refer to the lingering effects of a concussion (or effects that only arise in the weeks or months following a concussion) as post-concussion syndrome. In addition to headaches and loss of mental clarity, the most prominent indications of this syndrome include an unusually anxious or irritable emotional state, sleeplessness, loss of energy, lightheadedness and unusual sensitivity to light and noise. PTSD A person with post-traumatic stress disorder experiences a lasting or delayed reaction to the emotional pressures associated with exposure to life-threatening situations or situations that give the impression of threatening life or well-being. Classic symptoms associated with this reaction include repeated and uncontrolled activation of the body\u2019s \u201cfight-or-flight\u201d response, a spike in \u201cdown\u201d or negative thoughts and emotions, a pronounced desire to avoid reminders of an emotionally traumatic situation and unwanted reliving of such a situation while awake or asleep. Roughly 8 percent of all men exposed to life-threatening trauma will eventually develop PTSD, the federal National Center or PTSD reports; the PTSD rate for women exposed to such trauma is a much higher 20 percent. Concussions, PCS and PTSD Some of the circumstances that lead to the onset of a concussion qualify as emotionally traumatic situations or events. In a study published in 2014 in JAMA Psychiatry, researchers from 10 institutions located in France, Sweden, Denmark and Canada used data gathered from a French hospital between late 2007 and early 2009 to explore the connection between concussions, the development of post-concussion syndrome and the development of post-traumatic stress disorder. A total of 1,361 people contributed information to this project; 534 of these individuals had experienced significant head injuries, while the remainder had non-head-related traumatic injuries. One-quarter of a year after being injured, roughly a fifth (21.2 percent) of the participants with head injuries had symptoms that would qualify them for a post-concussion syndrome diagnosis. The participants affected by other types of injuries had a PCS rate of just over 16 percent. The researchers found that the post-traumatic stress disorder rate among those individuals with head injuries was 8.8 percent. In contrast, just 2.2 percent of those individuals with other types of injuries qualified for a PTSD diagnosis. Overall, the researchers concluded that a person with a concussion is substantially more likely to meet the criteria used to diagnose PTSD than the criteria used to diagnosis post-concussion syndrome several months after sustaining an injury. The study\u2019s authors note that some of the symptoms normally grouped together as post-concussion syndrome bear a strong resemblance to the symptoms found in people with PTSD who experience an unusual, recurring activation of their \u201cfight-or-flight\u201d response. These symptoms include such things as a heightened state of anxiousness, a heightened state of irritability and unusual noise sensitivity. The authors believe that, months after exposure to a traumatic situation, the presence of such symptoms has no clear link to post-concussion syndrome; rather, affected individuals are likely affected by PTSD-related overactivation of their bodies\u2019 natural short-term stress reactions.