Some of the advice in the other comments is dead wrong ('don't mention it', 'lie', 'fudge things'). Have you done any of the things in the past 10 years if Top

Some of the advice in the other comments is dead wrong ('don't mention it', 'lie', 'fudge things'). Have you done any of the things in the past 10 years if Top Secret, 5 if Secret (keeping in mind you might have to go TS before you've worked there 5 years)? Don't apply for a clearance, because they will find out eventually. If you apply then, be honest and fully truthful, and disclose everything. They are looking for signs of bad current judgement and things you are trying to hide that could be used to blackmail you. Also, "Have you considered X?" should be taken to mean 'Has you given more than a passing thought to X?'. If you had a relative die and thought 'I wonder why people commit suicide' that's one thing. If you thought 'Maybe I should kill myself', that is suicidal thought, even for a moment. Doesn't mean you're likely to do it. Does mean you should probably seek professional therapy to help you cope with your situation (doesn't mean you have a long time thing, just means at this moment you need some help coming up with coping mechanisms that work well enough).