Would almost 30 years in the military cause a personality disorder to develop?

He's been an officer for almost 30 years and due to annual deployments shows signs of PTSD. Based on the type of person he was before he joined the military, many of his old friends say he acts odd, like a person they've never met. He has a habit of lying, contradicting himself, looking down on others, showing no emotion and displaying other signs of narcissistic personality disorder. In other words, he's depressed and a possible narcissist. He's also been divorced for many years. Could his long military career have caused his dramatic change in personality?|||Narcissism is a different creature...involves embracing ones ego, never accepting blame, blaming others and otherwise not being realisitc about the people in ones life. PTSD is having nitemares, flashbacks, depression and anxiety. His deployment type (war zone? clerical? training?) will determine how likely he is to have it. PTSD folks from the military often have difficulty talking to others straight up about what they saw and what they did. They may deny, minimize or become addicts in order to numb the pain. This happens especially when serving violates moral or religious principles. The 2 disorders are not the same and can be found together or separate from each other. Encourage the person to seek VA mental health services. If found to be PTSD, the military will cover some of the costs of treatment.|||It absolutely could. However, narcissism and looking down on others, and those sorts of things generally are not considered to be normal PTSD symptoms from what I'm told. PTSD is usually more humbling in it's symptoms. This sounds more like an ego trip, honestly.|||OH YES, when you are in military, you see a lot of death , dealing with a lot things might friends dead or hurting, shortage foods, missing home, strugging, etc. it is not what you think it is more real bloody! you are in wars what do you think he had been thru? It must had changed him a lot|||Well he has changed his personality by being strict,thinking every moment counts, no emotions to live with. There are many other things if he's different and want to help him take him out to some sports gym or parks. If required take him to a psychologist. I hope best luck with him.|||Yes it had to cause his disorder. Like for example the soldiers that were in www II went home with many defects because once they arrived to their house they no longer acted like themselves any more.|||Two years did it for me!