A year taking course leads to indifference (6)
I believe the answer is:
apathy
'indifference' is the definition.
('apathy' can be a synonym of 'indifference')
'a year taking course' is the wordplay.
'year' becomes 'y'.
'taking' indicates putting letters inside.
'course' becomes 'path' ('path' can be a synonym of 'course'**).
'a'+'y'='ay'
'ay' going around 'path' is 'APATHY'.
'leads to' acts as a link.
(Other definitions for apathy that I've seen before include "Unconcern" , "Indifference - listlessness" , "Indifference, emotionlessness" , "Indifferent quality" , "Torpor" .)