No really @creative_writer . What I mean is that while your brain is thinking these unhelpful thoughts, you can actually train your brain to take a detour. For me, as I've mentioned to @Captain24 is that in the past when I was travelling down a unhelpful thought highway, I'd think of something that would cause a detour. For me, it was an ice cream truck. As soon as I saw that icecream truck in my thoughts, it changed the thought to being less intense. The more you practice this strategy, the more the brain is trained to travel down the detour route instead.
Put it this way. Your brain has lots of 'roads' and 'highways' (neutral pathways). Highways are the pathways that you naturally take because they are fast, smooth and easy (not necessarily helpful). So in order to build healthier 'highways', we need to travel down the 'roads in making' more often. This is hard at first. The road is bumpy, takes effort, takes time and hurts sometimes. But the more you travel down these roads, the smoother it becomes.
This analogy is just like your brain. For me the SH/suicide path was a major highway. I travelled on it pretty much every moment of the day....until I learnt to 'park' my ice cream truck there. I had to then make a detour. The detour was hard at first, but after a while, it became instinctive to travel down this new road (neural pathway).
This is how I 'changed my brain'.