Teen cycling during a couple of days with depression (6)
I believe the answer is:
dented
'with depression' is the definition.
(depression can mean a hole or dent)
'teen cycling during a couple of days' is the wordplay.
'cycling' indicates anagramming the letters.
'during' indicates putting letters inside.
'a couple of' shows that letters should be duplicated.
'days' becomes 'd' (abbreviation for days).
'teen' anagrammed gives 'ente'.
'd' doubled is 'dd'.
'ente' put into 'dd' is 'DENTED'.
(Other definitions for dented that I've seen before include "Made depression in through pressure or impact" , "Bashed in" , "Tended to be depresed" , "made an impression" , "Dinged" .)