Very much affected, as are one's neighbours (6,7)
I believe the answer is:
beside oneself
'very much affected' is the definition.
(to be beside oneself is to be very emotional)
'are one's neighbours' is the wordplay.
I cannot really see how this works, but
'one's' could be 'ones' and 'ones' is present in the answer.
'neighbours' could be 'beside' (I've seen this before) and 'beside' is found in the answer.
The remaining letters 'elf' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'as' acts as a link.
(Other definitions for beside oneself that I've seen before include "mad" , "Irrational, eg with worry" , "Lost control, distracted" , "Distraught" , "Overcome with worry" .)