Step-by-step explanation:
I think it depends on the certain kind.
Notifications can affect you mentally because it lets you know when something is ready or out, and your brain either thinks "cool I'll tend to it later", or "Ok I have to go check it out right now" It gives you less time to be spending time with others because your kind of already addicted at this point.
By physically, if there's a notification of like a stream or live video or something else interesting, it could cause you to stay up all night depending on the timeframe of the person starting it. You would start losing sleep and being around other people.
Could be emotional because if your tired, the more your on something, the more agitated, tired, and impatient you get. You would be spending so much time on a device, that you start distancing yourself from others and you just won't find happiness for long that way.