It's well known that the suicide rate in the military is linked to stress.
For example, back in 2005-6, the U.S. Navy was concerned when the suicide rate among submarine crewmen went to 35 per 100,000. At the time, the rest of the U.S. military Army had a rate about a third of that.
The suicide rate for submariners was eventually brought down to 20 per 100,000, mainly because the navy identified the causes of the stress and did something about it. But it's always understood that the suicide rate among the 20,000 submarine sailors will be higher, simply because it's more stressful work.
NEWS-02: US Submarine Veterans of WWIISubmitted by: Office on 1/21/2013
Al Konetzni, VADM Ret, delivered the Decommissioning speech for the SVWWII Organization when it closed at the Norfolk VA USSVI-SVWWII convention in 2012.
That speech is linked below.