The first question for an attorney representing a service member is whether his client has PTSD. Clients don't come in the door with their psychological issues written on their foreheads, and asking someone if they've been diagnosed with PTSD as a veteran or active duty is probably not the best way to start a succesful relationship. On the other hand, there are tactful ways to approach the issue. You can certainly ask, 'When did you last deploy? Were you in a combat zone?' However, that's dancing around the subject.
In my experience, the best way to approach possible psychological issues in a military divorce is the same way they should be approached in every divorce. Part of the client's intake process in every case should be obtaining the client's medical history. Whether you're dealing with a Fortune 500 executive who's been forced to take unwanted early retirement, or a PFC who's coming off several months in Afghanistan at a forward fire base in the middle of nowhere, you can't represent the client effectively without knowing his or her medical issues. You don't want to discover for the first time in the middle of a custody dispute that a military client's being treated for severe PTSD, any more than you want to discover that a civilian client's being treated for psychological problems caused by domestic violence or emotional abuse.
It's also worth remembering that PTSD Veterans or active duty service members diagnosed with PTSD have a broad spectrum of issues, and that none of them in any particular case may be genuine issues when the subject, for example, is successful parenting. Here's the bottom line. The guys on the other side will always be looking for something wrong with your client, whether it's PTSD or something else. Your attorney should immediately know everything about you that the other guys might use against you, so that whatever it might be, it can be explained and drained of prejudicial impact on your case.
If you're a PTSD veteran or former service member with PTSD, and you're looking for a military divorce lawyer, don't keep your PTSD a secret, and don't hire a lawyer who's afraid of helping you deal with it successfully in your military divorce.