Depression in gloomy place, on ecstasy (6)
I believe the answer is:
dimple
'depression' is the definition.
(dimple is a kind of depression)
'gloomy place on ecstasy' is the wordplay.
'gloomy' becomes 'dim'.
'place' becomes 'pl' (I've seen this in other clues**).
'on' means one lot of letters go next to another.
'ecstasy' becomes 'e' (informal term for the drug).
'dim'+'pl'+'e'='DIMPLE'
'in' acts as a link.
(Other definitions for dimple that I've seen before include "Fleshy dent" , "Small depression in flesh" , "Slight depression (in the skin)" , "Attractive indentation in face" , "Natural dent in skin" .)