In the U.S. if you express suicidal ideations, your professional flying career is probably over (unless you somehow make it an alcohol or gender identity issue). If you keep the thoughts to yourself, you keep flying.
"He flew nearly three more years, without incident, before he resigned in 1982 with severe obsessive-compulsive disorder, anxiety and depression."
And once again, I re-state - you will show obvious signs of regular "clinical depression" if you have suicidal tendencies. You may be able to keep your suicidal thoughts to yourself (only in about 30% of reported cases) - but the severe depressive bouts will be obvious to any adult with a modest degree of perception.