Yeah, my username was my last radio callsign in Vietnam. That was after the Army switched from the 'six' system to random number callsigns. Before that I was Itchy Click One-Six and my RTO was One-Six Oscar. Years afterward I learned that my first Itchy Click One-Six Oscar killed himself shortly after he got back from Vietnam. And I've also lost other VN vet friends that way over the years.
For today's troops the statistics probably would be even higher if not for the far greater level of mental health services available.