One of the issues that need to be addressed re mentally fit to fly is the bullying tactics of management ignoring a pilots physical as well as mental health.
Not only the trident crash but I witnessed one of the managers of the time trying to force a new command take an aircraft out of home with a technical deficiency that was not allowed. We were then put onto airport standby just for spite as there wasn’t a serviceable aircraft at Heathrow.
It was similar during the IRA bombing campaign when we were volunteered to fly Belfast and BALPA had to step in as our life insurance wasn’t valid flying into a war zone. The truth about the number of bombs placed on BEA aircraft was and is still withheld.
It wasn’t the only airline that I witnessed threats to keep an unwell pilot flying especially with fatigue considerations due to paring the crew numbers below a safe number.
I remember two suicides and a couple of physical arguments including one on the flight deck.