I don't know if he invested it in a highily volatile and risky platform or that he fell scamming victim.
The main cause of all this is what we call risk management, which involves knowing how to fit into any risk before you can decide whether to go into it or not. There are certain risks that are meant for people based on their financial status, and that doesn't mean if you try to fit into the risk, you won't succeed. No, but it will have just less possibility for you to succeed in the risk, which is the same as the risk that your in-law takes.
If he focused on going for the risk based on his income, he would not be in the situation that he is in because he will not have to accumulate any debt. The main problem that will be disturbing him and make him start acting strange is due to the money that he is going to pay because if he only lost his capital, he would have the strength to lend some funds and raise his business, but with debt, he cannot do that because he needs to pay the former debt before he can get another one, and there is no source to get that, so that is capable of making him mentally ill.