Not quite but closer than I would have suspected:
Suicide attempt fatality rate: 9%
Everest attempt fatality rate: 2%
Sources: Climber fatality from attempts through 2006:
http://www.adventurestats.com/tables/EverestAgeFat.shtml
Suicide estimate from NIH:
http://www.nimh.nih.gov/health/publications/suicide-in-the-us-statistics-and-prevention/index.shtml