Appendix B

Using the methodology of Kessler et al,³⁷ the National Population Health Survey (NPHS) measures a major depressive episode with a subset of questions from the Composite International Diagnostic Interview. These questions cover a cluster of symptoms for a depressive disorder, which are listed in the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R).³⁹  The question numbers refer to those used in the mental health section of the NPHS questionnaire. There are three possible paths through these questions: “yes” to 2, then 3 to 13; “no” to 2, “yes” to 16, then 17 to 26; and “no” to 2 and “no” to 16.

• 2       During the past 12 months, was there ever a time when you felt sad, blue, or depressed for two weeks or more in a row?
  • (Yes - go to 3; No - go to 16)

• 16      During the past 12 months, was there ever a time lasting two weeks or more when you lost interest in most things like hobbies, work, or activities that usually give you pleasure?
  • (Yes - go to 17; No - end)

• 3/17    For the next few questions, please think of the two-week period during the past 12 months when: 3. these feelings were worst. 17. you had the most complete loss of interest in things.
            During that time how long did these feelings usually last?
  • (All day long; Most of the day; About half of the day; Less than half the day)

• 4/18    How often did you feel this way during those two weeks?
  • (Every day; Almost every day; Less often)

• 5       During those two weeks did you lose interest in most things?
  • (Yes; No)

• 6/19    Did you feel tired out or low on energy all of the time?
  • (Yes; No)

• 7/20    Did you gain weight, lose weight, or stay about the same?
  • (Gained weight; Lost weight; Stayed about the same; Was on a diet)

• 8/21    About how much did you gain/lose?

• 9/22    Did you have more trouble falling asleep than you usually do?
  • (Yes; No)

• 10/23   How often did that happen?
  • (Every night; Nearly every night; Less often)

• 11/24   Did you have a lot more trouble concentrating than usual?
  • (Yes; No)

• 12/25   At these times, people sometimes feel down on themselves, no good, or worthless. Did you feel this way?
  • (Yes; No)

• 13/26   Did you think a lot about death — either your own, someone else’s, or death in general?
  • (Yes; No)

A value of 1 was assigned to any “yes” answer to the “yes/no” questions. For questions 8 and 21, a score of 1 was assigned if the change in weight was at least 10 pounds (4.5 kilograms). For questions 10 and 23, a score of 1 was given to respondents who reported having trouble falling asleep every night or nearly every night. Those who replied “yes” to question 2, and whose symptoms lasted all day or most of the day, and had occurred every day or almost every day, had a maximum possible score of 8. For those who responded “yes” to question 16, and whose symptoms lasted all day or most of the day, and had occurred every day or almost every day, the maximum possible was 7. Respondents who replied “no” to questions 2 and 16 scored 0.