( CNN ) -- Q : Sgt . Robert Bales has been accused of killing 16 Afghan civilians . He served three tours in Iraq before this and his lawyer says he may have been suffering from post-traumatic stress disorder or a traumatic brain injury . What 's the link between violence and those disorders ? A : Psychiatrists understand some types of aberrant behavior pretty well and can do things to help resolve it . But , unfortunately , in other instances -- and often the most interesting ones -- we can only mumble generalities that require no special expertise and that offer no hope for a diagnosis or treatment . Take the case of U.S. Army Sgt . Robert Bales , accused of massacring 16 Afghan men , women and children while they slept unprotected in their village . The first thing a psychiatrist would want to know is whether the person who committed such a heinous act was psychotic at that time , meaning out of touch with agreed-upon human reality . Did he perform the killings as a result of deeply held false beliefs or in response to hearing voices commanding him to act ? If yes , then although the tragedy remains , the psychiatric mystery is solved . But at this point , although Bales has reportedly told his lawyer he remembers nothing about the night of the massacre , there is no evidence he was psychotic immediately before the killing spree . Nor do we have any evidence at this point that the killings were motivated by some larger political purpose , which might also explain , but certainly not justify , them . So why would someone who had appeared normal to everyone around him suddenly commit such a hideous act ? Army reviewing PTSD evaluation program . Much has been made in the media about the fact that Bales was on his fourth deployment . Moreover , he had suffered mild traumatic brain injury in Iraq . Traumatic brain injury can cause a wide range of mental difficulties , from poor decision making and memory to increases in impulsive behavior , irritability , depression and personality change . So how likely is it that Bales ' traumatic brain injury explains the accusation that he massacred 16 Afghan villagers ? The answer is : not very likely . Why ? Consider , as alternative possible explanation , mania . Mania is often characterized by the sudden onset of bizarre , agitated behavior in public and it is not necessarily related to traumatic brain injury . Traumatic brain injury almost never causes otherwise solid citizens to ruthlessly massacre men , women and children . Thousands upon thousands of people develop severe manic episodes every year . Thousands upon thousands of service men and women have been multiply deployed and have suffered various levels of traumatic brain injury , and yet there is only one Bales . That is why it does n't fit very well . Mass murder is just about as rare in people with brain damage as in people without brain damage . Note that I said `` just about . '' In fact , organic brain damage can be a cause of mass violence . Probably the most classic example of this in American history was the case of Charles Whitman , who went on a shooting spree from atop the University of Texas tower that resulted in the death of 16 people . Although he was under multiple stressors at the time of the incident , he was found to have a brain tumor in the `` rage area '' of his brain ( i.e . the amygdala ) upon autopsy . In the case of Bales , if he is guilty of the massacre , his actions may eventually be found to be related to a clearly causative organic factor . But my clinical experience tells me not to bet on this . It happens , but pretty rarely . When people behave in unexpected ways for no good reason , it often turns out that when the full story of their lives is understood , the behavior no longer appears as unexpected . That which is neither clearly linked to either a medical or psychiatric illness is very likely intertwined in a person 's longstanding personality . So , I suspect that if 100 psychiatrists were told that a previously normal service person massacred 16 civilians and was neither medically impaired nor psychotic , the majority of them would immediately suspect that the person in question might not have been as normal across his life as initial reports suggested . In fact , as more comes out about Bales this appears to be the case . It now appears that he was involved in fraudulent business dealings . What makes the case so strange , however , are the multiple contrasting reports of his remarkably caring and selfless behavior on numerous occasions and his status as something of a small town hero . I seem to end many of my CNNhealth pieces with some type of comment about how unsatisfying our current level of psychiatric understanding is . This pieces , alas , is no different in this regard . Frankly , at this point nothing in Bales ' actions makes psychiatric sense . On the other hand , how many highly admired , hard-working , patriotic , caring small-town heroes are embroiled in financial fraud or may have other dark behaviors in their backgrounds ? Maybe the fact that Bales himself may not make sense is the best place for us to start in our understanding of the horrible events in Afghanistan .
A lawyer for Sgt . Robert Bales says the soldier may have been suffering from TBI , PTSD . Score: 7 Raison : The backstory to someone 's life is just as important as the current situation .