Yup, suicidal attempts are often impulsive, so any barrier (in this case literally) even if it's relatively easy to get around, reduces suicide rates. Here's another study, this time on firearms:

https://med.stanford.edu/news/all-news/2020/06/handgun-owner...

> The researchers found that people who owned handguns had rates of suicide that were nearly four times higher than people living in the same neighborhood who did not own handguns. The elevated risk was driven by higher rates of suicide by firearm. Handgun owners did not have higher rates of suicide by other methods or higher rates of death generally.

Suicide attempts by firearm are far more likely to complete than most other means, ergo, suicide death rates are higher among those that have firearms.