### Clue: Addict invested in retro fashion bags (8)
### Answer: TROUSERS 
 ### Explanation: Definition: bags
 USER(an addict who, well, uses drugs) **contained in**(invested in) **reversal of**(retro) SORT(a kind, as in "his remarks were compliments of a sort/fashion").
Defn: Clothing of which "bags" are examples.