My sister killed herself 9 and a half years ago, and I'm pretty convinced that she'd still be alive if she didn't have immediate access to what she used(+).

Due to the method, we know when she obtained it, and the circumstances around that. She got it when there were suicides in her local community, and in retrospect she had probably been thinking about it at the time. She definitely had some mental health issues at the time centered around overwork. She kept it for years, and finally used it when she had a minor setback at work.

(+ not a gun)

Quebec's suicide prevention strategy combined evidence-based practices, and managed to halve the suicide rate from 1999 to 2010, and it's been declining ~2% every year since 2010. Everything they do should be studied by anybody interested in this topic since it works. Things like restricting guns or drugs just means they will leap off a bridge or other method, it doesn't address the root causes which Quebec managed to do.