Break down article sanely? Madly! (7)
I believe the answer is:
analyse
'break down' is the definition.
(I know that break down can be written as analyse)
'article sanely? madly' is the wordplay.
'article' becomes 'a' (English indefinite article).
'madly' indicates anagramming the letters.
'sanely' anagrammed gives 'nalyse'.
'a'+'nalyse'='ANALYSE'
(Other definitions for analyse that I've seen before include "Examine the component parts" , "Scrutinise, break down" , "Dissect" , "Resolve into components" , "Break down into constituent parts" .)