Dr. Kutcher would certainly know the differences in these conditions.  He is a sports neurologist and an expert in neurological injuries from sports (including concussion, peripheral nerve injury and "stingers," among others), where roughly 90 percent of his time is devoted to concussions. 

According to Kutcher, CTE does not necessarily cause suicide, either.  CTE affects cognition, memory, programming executive function, attention span, depression and mood swings, in addition to many other symptoms.  However, he noted, "Head trauma is a risk factor for CTE, which is a risk factor for depression, which is a risk factor for suicide."  He added: "What I see every week is people forgetting that depression is common to begin with – there are factors that lead to an increased rate of suicide."  Kutcher feels that, unfortunately, the media has contributed to the football/head trauma-suicide connection by oversimplifying the message. 

"What is more likely to decrease life expectancy – football or riding in a car?  We know how dangerous cars are, but we do it all the time.  The risk we're experiencing with regards to football is a reaction to finally understanding that there is a risk, and people are having a difficult time framing that risk to wrap their heads around," Kutcher stated.  He believes that parents should be more concerned about children playing with the proper equipment, that children are taught to avoid head-to-head collisions and that coaches and parents are better able to identify head injuries.

Despite downplaying concerns about a connection between concussions and suicide, Kutcher emphasizes the importance of finding a properly trained doctor if a concussion has occurred. "You should really try to seek care from a physician who is trained at doing this,"  he said. "Everyone is trying to say they can manage this injury, but these are medical questions that require someone who understands the depth and breadth of brain function over time." 

Sources:

Christopher Regal with Dr. Jeffrey Kutcher.  Telephone Interview.  August 23, 2012.