I have been thinking about this and I think I needed bringing it up here for discussion. Are you a trader, or do you know any real traders, someone who consistently follows the market? Have you noticed them on any sort of substance?
I don't completely agree that traders become substance abusers, because there are many traders in the world who are still trading even though they are not substance abusers. As far as I can see, there are some people I know who don't even smoke.
However, it is not entirely true that these things do not happen at all, because those who come to trade without trading knowledge and suffer huge losses can go down this path from depression, and traders can also become drug addicts due to various stresses.
However, I think we do not need to worry too much about these negative things. If we trade according to the right rules and manage our life cycle according to a specific routine, then I do not think we will have to face any such problems.