It could be a mental health problem or it could be drug usage or both. Drug use might explain why his behavior has changed so dramatically. Without more information, those are my best (educated) guesses.
I’m wondering, when you and he were married, were there no signs? Was he truly that different? Looking back, were there behaviors or concerns that were overlooked? Those are just a few questions that could help you better understand what has happened to your ex.
You made the statement that because the two of you have separated, you have “no influence over him at all.” Even when you were together, you likely had very little influence over his behavior.
If his behavior continues, then he might end up being arrested. Realistically, there is very little or nothing that you can do to change the potential eventualities. People are free to make choices that are detrimental to their lives but they can only be forced into treatment against their will under dire life and death circumstances. You can suggest treatment and offer your support but realize that he may not take your advice or want your support. Eventually, he might make better choices or seek professional help but it’s his life and he will do with it what he wants. He will have to pay for the consequences of his choices. This is equally true for the mentally ill. Please take care.
Dr. Kristina Randle