Three suicides in a week. Twenty-two among Regular Force members in 2011, an unknown number is 2012. [Evidently reservists are still treated as second-order soldiers by the system - plus ça change...] There will be more. There are things that can be done to prevent them, but not all of them. Like the former Yugoslavia and Somalia, Afghanistan's casualties will continue to mount long after the last troops leave theatre. This is a fact of war.
In past wars, armies were demobilised following the end of conflict and the soldiers faded away into civilian life. Most served only a few short years, either until they were invalided out, killed, or the war ended. They would fade into civilian life in the hundreds of thousands. Some would remain traumatised and unable to function, others would find jobs and families and new lives in a country that understand it was universally at war. Today, armies are already small and do not shrink by much post war, and life for most does not change. Soldiers now have careers and many carry on serving for years or decades. Those that return to civilian life, return to a society that unlike in the past, was never really at war and cannot connect to them. More will end their lives.