If you have long term depression, it can be a bear to deal with and remedies seem to be spotty at best in terms of effectiveness. I know Johnny Hopkins is doing trials on psychedelic mushrooms for treatment, unfortunately I don't know of any ketamine treatment in the area.

If you're in real trouble with S. ideation, take Folic Acid with a B12 supplement as it has been found to have over 40 percent improvement in preventing episodes. https://biologicalsciences.uchicago.edu/news/features/folic-acid-reduces-suicide-attempts

It's relatively cheap with no real side effects other than masking B12 deficiency, hence adding B12 supplement.