I know you can get a Secret and I have heard you can get a Top Secret depending on the agency. Though some agencies give random drug tests to people with Top Secret clearances and many contractors also have their own testing policy.
They do however ask about drug usage both on the application and when doing their investigation.
Id be surprised for TS I looked at a job at Hanslope Park which would have required DV (TS) clearance and you had to have drug tests. Didn't get a second interview was well over qualified - but one has to keep the DHSS happy or id lose my nugatory benefits.
They do however ask about drug usage both on the application and when doing their investigation.