I don't think that anyone ever uses this to mean "drunk." It usually means HAVING TOO MUCH (WORK for example) TO DO. IT IS USUALLY A FRUSTRATING FEELING.

Overwhelmed has nothing to do with being drunk. It means that you feel you have too much of something and have difficulty in coping. You may be overwhelmed with work - you have too much and feel you have difficulty in coping with it. You may be overwhelmed with emotion - you feel very desperate or sad with your emotions dominating your thinking. It is not exclusively a bad thing. A mother might cry at her daughter's wedding because she is overwhelmed with the emotions of joy and happinesss.

Hello, "Overwhelmed" is no synonym with being drunk at all , It is usually used passive to mean as you mentioned to defeat someone , or to cause someone to feel a sudden strong emotion ,but could also be used in a positive sense " She was overwhelmed by all the flowers she received " . Other ways to express " being drunk " : There are lots of slang words to indicate that state such as : " besotted , blind drunk , blotto , crocked , loaded , smashed , soaked ,tipsy , narcotized , half-seas-over, high , mellow , drunken ,boozy , orgiastic beery ,slopped , fuddled ......"

He is overwhelmed. - Hi is miserable, sad and so on.