Specifically, Kessler's instrument asks how often, during the past 30 days, the respondent felt:

• So sad that nothing could cheer you up? (ASAD)

• Nervous? (ANERVOUS)

• Restless or fidgety? (ARESTLESS)

• Hopeless? (AHOPELESS)

• That everything was an effort? (AEFFORT)

• Worthless? (AWORTHLESS)

For each of these questions, respondents selected one of the following responses from a flashcard: "none of the time," "a little of the time," "some of the time," "most of the time," "all of the time."

Specifically, interviewers asked, "Altogether, how much did these feelings interfere with your life or activities: a little, some, a lot, or not at all?" Those who answered "a little," "some," or "a lot," were asked the aforementioned question for FBADUNABLE about how many days, during the past 30 days, they were totally unable to work or carry out their usual activities because of these feelings. Those who responded to FBADUNABLE with a number lower than 30 were asked how many days they had to cut down on what they did because of these feelings (FBADCUTDOWN). These follow-up questions were not part of the tool designed by Kessler to measure nonspecific psychological distress or severe mental illness.

Other follow-up questions to variables from the Kessler 6 Scale asked whether respondents who had such feelings at least "some of the time" during the past 30 days, had such feelings more often than usual for them, less often, or about the same as usual (FBADHOWOFT). Those who responded "more often" were asked whether this was "a lot more, somewhat, or only a little more often than usual" (FBADMORE). Those who responded "less often" were asked whether this was "a lot more, somewhat, or only a little less often than usual" (FBADLESS).