Just like to talk?
"Perhaps you became more talkative to make up the difference in a relationship with a partner who didn’t talk much.
Compulsive talking Garrulity, can be associated with dementia, or cognitive impairment"
Chatterbox, Long-winded. Neurologist?
Others may indeed be lonely.
I have known a few husbands that have purposely turned off their hearing aids if their wives were extra chatty!
I have also observed that morphine can indeed produce garrulity. One normally laconic gentleman I know won't shut up after he's taken his meds; I don't know how long the effect lasts but it was at least twenty minutes before I could politely get off the phone to him.
However. The key question is: is this talkativeness usual in the person you are describing? If anything has changed, and doesn't have an obvious and harmless explanation, that's when you need a professional opinion.