The behavior you described does not necessarily indicate any particular mental health disorder. If I knew more about him and had a chance to interview him, I would have greater insight into what is wrong. Otherwise, this might be who he is, his personality.
You called him a very close friend. That would suggest you’ve known him for a while. If so, then you would have likely been continuously experiencing these behaviors. But then you also said that his behavior is worsening “day by day.” Did something prompt this change? Did something happen that caused his behavior to change? A physical injury? A brain injury?
If you suspect that something is wrong, suggest he seek professional help. If it is a personality issue, then you’ll have to decide if you want this person in your life. You don’t have the power to change him and thus whether or not you want to continue this relationship will be up to you.
To stay friends is a personal decision. Ultimately, how you move forward in this relationship rests upon whether you can tolerate his behavior, no matter the cause. Good luck with your decision. Please take care.
Dr. Kristina Randle