In previous columns, I've talked about a number of issues related to posttraumatic stress disorder. One aspect of PTSD that I have yet to discuss is one that is rather controversial and not commonly talked about-using PTSD as an excuse for unsavory and illegal behavior.

At least once a month, there seems to be a new case in the media depicting a veteran who has been convicted of a serious crime such as drug trafficking, child pornography, theft, rape, and even murder. In many of these cases, a diagnosis of posttraumatic stress disorder is cited by the veteran's attorney as the cause of the behavior.

So, can PTSD cause criminal behavior? Yes and no. There is no doubt that PTSD can cause a person to make bad choices that lead to antisocial behaviors. Increased use of alcohol or drugs can lead to driving while intoxicated, domestic violence, and petty theft to support their drug or alcohol use. Increased physiological arousal, which causes the service member to always be on-guard, can lead to violent behavior that is out of proportion to a perceived threat. There are even cases in which combat veterans with PTSD have been found not guilty of murder when they were put in a situation, which reminded them of a previous stressful combat experience, and they felt they were defending themselves against an enemy combatant.

It's important to keep in mind that these are extreme cases, particularly the last one. In most cases, PTSD does not lead to criminal behavior. Much of what is seen on this issue in the media is a result of savvy lawyers conjuring up defenses for their clients that would have likely committed the crime regardless if they had PTSD or not. Lawyers know that the average citizen sitting on a jury will have a great deal of sympathy for the veteran, which they hope will result in a favorable outcome for their client.