Have habit that's a bit much - no more doctors keeping tabs (9)
I believe the answer is:
overdress
'have habit that's a bit much' is the definition.
(habit can mean one's clothing)
'no more doctors keeping tabs' is the wordplay.
'no more' becomes 'over' (over can mean finished or done).
'doctors' becomes 'drs' ('Dr' can be a synonym of 'doctor').
'keeping' is an insertion indicator.
'tabs' becomes 'Es' (multiple Ecstasy tablets).
'drs' going around 'es' is 'dress'.
'over'+'dress'='OVERDRESS'
(Other definitions for overdress that I've seen before include "Do servers? (anagram)" , "to look very smart" , "Wear too elaborate clothing" , "outer garb" .)