I guess it depends on your background, how long you have been working and in what field, etc. I just used self-employed, school, or working on own projects to fill in the gaps. But, I never hid that I had issues in the first place, I just don't think they are germane to one's CV. If it got serious in an interview I negotiated time off to see my therapist, etc. The CV says what you are working on, isn't supposed to be about health or hobbies or other issues that don't have anything to do with what jobs you are applying for. Issues are part of taking/not taking a particular job.