Gadget item somehow messing with our heads? (5)
I believe the answer is:
gismo
'gadget' is the definition.
(I've seen this before)
'item somehow messing with our heads?' is the wordplay.
I cannot quite understand how this works, but
'heads?' could be 'is' (heading is a kind of being) and 'is' is present in the answer.
This explanation may well be incorrect...
(Other definitions for gismo that I've seen before include "Device of American" , "Ingenious gadget" , "Fancy device" , "Gadget (colloq.)" , "Useful (but unspecified) device" .)