And you know this based on what? To me it seems the opposite is true. If you have the means, it's more likely you'll do something. If it's too complicated, you might just give up, or not even have a thought that you could do something like that. Opportunity makes a thief.
Anecdotal evidence: I was close to suicide a couple of times in my life, and believe I would have done it if I had had a weapon just lying around or within easy access. Thankfully I did not. (Non-US, access to guns highly restricted.)