I have held several security clearances of varying levels over the years. During interviews for every single one, I was asked about past drug use, in particular

I have held several security clearances of varying levels over the years. During interviews for every single one, I was asked about past drug use, in particular drug use within the past 7 years. (Note that they also ask about all psych/therapy stuff- though family, grief and combat related PTSD counseling are off-limits.) Some of those interviews took place in locations where marijuana was legal at the state level, but it is everywhere in the US illegal at the federal level so they ask. And while it wouldn't necessarily kill your clearance, recent use was definitely a black mark that would need to be analyzed and discussed with you and slow things down. Funniest moment in all my clearances: you need to provide a neighbor to be interviewed, having just moved and not knowing anyone well I picked the only neighbor I knew the full name of; turns out he was a registered sex-offender! Didn't kill my clearance, but did slow everything down and mean I got to spend a lot more time talking to men in suits than my colleagues did. Sounds similar to what is happening here, honestly.