I cant remember which Topic I posted on before. It could possibly have been AIBU for traction. But basically I posted about our ongoing struggles with my BIL who just could not get his life together and in recent years had gambled (been scammed) out of his life savings, could not hold down a job, could not hold onto a relationship and was totally dependent on by DH for his survival without any feeling of shame or remorse.
Update is that he has been diagnosed with a brain lesion. This brain lesion is probably not likely responsible for his behaviour but more likely responsible for his lack of reasoning and logic which just compounds an already difficult personality.
It has been very difficult to determine what he is responsible for as he has always been this way to a degree and what is now just worse because his cognitive thinking is compromised.