When I did my SF 86 I denied by ignorance and (I was filling up the form with a hurry) using control substance in the (controlled substance for 7 years question). On the polygraph examination in the Pre interview section, the examinator discuss every question with me and I told him that I did use control substance without prescription. My preliminary result was positive before a leave the suite. Can this affect my background investigation in some way?
A lack of candor on a clearance application absolutely can affect your ability to be granted a security clearance. You did not provide enough information for me to advise any further.