The military mental health system isn’t really a resourced system at all. The linked article above points at the limited days and working hours that the system is actually staffed, but the problems are more deep-rooted.
There is no functioning acute mental health response system. Even though one of my chaps had his crisis during the working day there was zero response as he lived off base - the system is reliant on the patient coming to them. Nor is there any rapid response if the service person does subsequently come on to base (in this example, signing-out his pistol and taking it home).
Military mental health departments are also few and far between, expecting patients to travel large distances, even from main operating bases. If service transport is made available the distressed patient gains zero priority and can find themselves sharing vehicles and being driven around the country with the routine airport/pool drill/simulator/HQ run (all genuine examples).
Arguably the biggest barrier that prevents individuals from coming forward are the career implications. It can take a number of years to fully recover from service-attributable mental health issue yet the Service is usually not that accommodating, preferring a medical discharge. Inexcusably a medical discharge can be set in motion before a course of treatment has concluded or, in some cases, before mental health treatment has even started.
Service mental health issues are common and usually treatable. Sadly the MoD has never really grasped those two simple facts.