Respondents did not pass these screening questions if they:

• Did not feel sad, blue, or depressed for 2+ weeks in a row (a "No" in DEP2WKEV); or

• Volunteered in DEP2WKEV that they were on medication/anti-depressants; or

• Reported that their feeling sad, blue, or depressed lasted "Less than half of the day" in DEPDAYAMT; or

• Reported that their feeling sad, blue, or depressed lasted "Less often" in DEPHOWOFT; or

• Had an unknown response in DEP2WKEV, DEPDAYAMT, or DEPHOWOFT.

For more information on the dysphoric mood questions, see DEP2WKEV.

According to the Field Representative's Manual for 1999, this set of questions was included "to determine if the Sample Adult has had or still has a loss of interest in things, indicating undiagnosed depression, in the past 12 months and, if so, how it affected them physically and emotionally, how long it has affected them, how they dealt with these problems, and how much these problems interfered with their life or activities."

The periodic mental health section of the 1999 NHIS includes questions taken from the CIDI-SF screening scales for major depression, generalized anxiety disorder, and panic attacks. More information on the generalized anxiety disorder questions can be found in WOR1MO. For more information on the panic attack questions, see PANICYR.

Respondents with an affirmative response in DEPLIFUN (IPUMS NHIS code 2) were told, "For the next few questions, please think of the two week period during the past 12 months when you had the most complete loss of interest in things," and then were asked a second screening question for anhedonia:

• During that two week period, did the loss of interest usually last all day long, most of the day, about half the day, or less than half the day? (DEPLIDAYAMT)

Respondents who indicated, in answer to the question associated with DEPLIFUN, that they were on medication/anti-depressants received no further questions on major depression related to anhedonic symptoms.

Respondents who answered "All day long," "Most of the day," or "About half of the day" to the question associated with DEPLIDAYAMT were asked a third screening question for anhedonia:

• During those two weeks, did you feel this way every day, almost every day, or less often? (DEPLIHOWOFT)

Respondents who passed the first two screening questions (DEPLIFUN, DEPLIDAYAMT) and who answered "Every day" or "Almost every day" to DEPLIHOWOFT received a series of questions on symptoms associated with anhedonia. Respondents who did not pass all three anhedonia screening questions (DEPLIFUN, DEPLIDAYAMT, DEPLIHOWOFT) received no further questions on major depression related to anhedonic symptoms.

As mentioned above, respondents only received the first anhedonia screening question (DEPLIFUN) if they did not pass all three screening questions in the dysphoric mood section. The screening questions in the dysphoric mood section mirror the screening questions on anhedonia, except that the symptom referenced in the dysphoric mood questions is "feeling sad, blue or depressed," rather than "loss of interest in things that usually give pleasure." Respondents who passed all three of the dysphoric mood screening questions were asked a series of dysphoric mood symptom questions similar to the series of questions asked about anhedonic symptoms. For more information on the dysphoric mood-related questions, see DEP2WKEV.

Respondents who passed the three screening questions for anhedonia, DEPLIFUN, DEPLIDAYAMT, and DEPLIHOWOFT, received symptom questions about the following:

• Felt more lethargic during 2+ weeks lost interest in activities, past 12 months (DEPLILETH)

• Weight gained/lost/same during 2+ weeks lost interest in activities, past 12 months (DEPLIWT)

• (For respondents whose weight changed) Amount of weight change during 2+ weeks lost interest in activities, past 12 months (DEPLIWTAMT)

• (For respondents whose amount of weight change was unknown) Weight changed 10+ pounds during 2+ weeks lost interest in activities, past 12 months (DEPLIWT10)

• Had trouble sleeping during 2+ weeks lost interest in activities, past 12 months (DEPLINSOM)

• (For respondents who had trouble sleeping) How often had trouble sleeping during 2+ weeks lost interest in activities, past 12 months (DEPLINSOMOFT)

• Had trouble concentrating during 2+ weeks lost interest in activities, past 12 months (DEPLICONCEN)

• Felt worthless/no good during 2+ weeks lost interest in activities, past 12 months (DEPLINOGOOD)

• Thought about death during 2+ weeks lost interest in activities, past 12 months (DEPLISUICID)

Respondents who reported feeling lethargic, having trouble concentrating, feeling no good, and/or thinking about death (a "Yes" to DEPLILETH, DEPLICONCEN, DEPLINOGOOD, and/or DEPLISUICID) were asked further supplemental questions about the length of time they lost interest in pleasurable activities and about the effects of these symptoms on their lives. Those who reported that their weight changed by 10+ pounds (a "Yes" response in DEPLIWT and either a report of 10+ pounds in DEPLIWTAMT or a "Yes" response in DEPLIWT10) and those who reported having trouble sleeping every night or nearly every night (according to DEPLINSOM and DEPLINSOMOFT) were also asked these supplemental questions. Specifically, these supplemental questions were:

• Total number of weeks lost interest in activities during past 12 months (DEPLIWKNO)

• Most recent month lost interest in activities 2+ weeks (DEPLIWHENMO)

• Most recent year, 1998-2000, lost interest in activities 2+ weeks (DEPLIWHENYR)

• Told doctor about losing interest in activities 2+ weeks during the past 12 months (DEPLITOLDDR)

• Told health professional about losing interest in activities 2+ weeks during the past 12 months (DEPLITOLDHP)

• Used medication/drugs/alcohol to cope with loss of interest in activities (DEPLIDRUGALC)

• Amount loss of interest in activities 2+ weeks during the past 12 months interfered with life (DEPLIINTFERE)

The skip pattern found in the NHIS survey instrument for the first screening question, DEPLIFUN, differs slightly from that in the WHO CIDI-SF instrument. In the NHIS CIDI-SF instrument, respondents who indicate that they are on medication/anti-depressants receive no further questions on major depression related to anhedonic symptoms. In contrast, according to the scoring guide for the World Health Organization's CIDI-SF, respondents who volunteer that they are on medication/anti-depressants in DEPLIFUN go on to the second screening question for anhedonia (DEPLIDAYAMT).

The WHO CIDI-SF skip pattern for the second screening question for anhedonia, DEPLIDAYAMT, is also different from that in the NHIS instrument. In the WHO CIDI-SF instrument, only respondents who report experiencing a loss of interest in pleasurable activities "All day long" or "Most of the day" in DEPLIDAYAMT receive the third screening question (DEPLIHOWOFT). However, in the NHIS instrument, respondents who answer "About half of the day" in DEPLIDAYAMT also go on to DEPLIHOWOFT.

Because of these differences, scoring the screening scale for major depression yields different results, depending on whether guided by the WHO CIDI-SF instrument or the NHIS version of the instrument (see below).

According to the Appendix on Adult Mental Health Documentation included in the 1999 NHIS Survey Description, the "NCHS suggests that individual CIDI-SF items [as used in the NHIS] not be used for purposes beyond those recommended by the World Health Organization (WHO)." The Survey Description then directs users to the WHO's website for instructions on how to calculate the probability of psychiatric diagnosis based on responses to the CIDI-SF items.

According to the WHO CIDI-SF guidelines, respondents must pass all three screening questions in the anhedonia section (DEPLIFUN, DEPLIDAYAMT, DEPLIHOWOFT) to receive further questions on depressive symptoms. Respondents who do not pass the first screening question, DEPLIFUN, receive a score of 0 (zero probability of psychiatric caseness for major depression with anhedonia). Those who pass the first screening question (DEPLIFUN) but not the second two (DEPLIDAYAMT, DEPLIHOWOFT) receive a major depression score of 1.

Respondents who pass all three screening questions on anhedonia and answer the depressive symptom questions receive one point for each of the following responses about depressive symptoms:

• "Yes" in DEPLILETH (Felt more lethargic than usual)

• "Gain," "Lose," or "Volunteered 'both gained and lost weight'" in DEPLIWT (Gained and/or lost weight) and "10+" in DEPLIWTAMT (Amount of weight change 10+ pounds) or "Yes" in DEPLIWT10 (Weight changed 10+ pounds)

• "Yes" in DEPLINSOM (Had trouble sleeping) and "Every night" or "Nearly every night" in DEPLINSOMOFT (How often had trouble sleeping)

• "Yes" in DEPLICONCEN (Had trouble concentrating)

• "Yes" in DEPLINOGOOD (Felt worthless or no good)

• "Yes" in DEPLISUICID (Thought about death)

Summing the number of endorsed items and adding it to the one point received for passing DEPLIFUN results in a major depression score ranging from 1-7. Respondents with a score of 3 or more are classified as a probable case for having major depression with anhedonia.

First, for the second screening question (DEPLIDAYAMT), the NHIS instrument used less stringent criteria in its skip pattern than did the WHO CIDI-SF instrument. With the NHIS instrument, respondents who reported experiencing a loss of interest in pleasurable activities "All day long," "Most of the day," or "About half the day" in response to the second screening question (DEPLIDAYAMT) were questioned further about anhedonia. In contrast, only respondents answering "All day long" or "Most of the day" to DEPLIDAYAMT were questioned further about anhedonia using the WHO guidelines. By definition, therefore, more people will be classified as probable cases for major depression using the NHIS version of the CIDI-SF than with the WHO version of the CIDI-SF.

Second, as mentioned above, according to the CIDI-SF scoring guide published by the World Health Organization, respondents who report taking medication/anti-depressants in DEPLIFUN are questioned further about their symptoms of anhedonia. In contrast, in the NHIS version of the CIDI-SF respondents who indicate that they are taking medication/anti-depressants receive no further questions in the anhedonia section. However, an article published by the Department of Health and Human Services, based on these NHIS data, classified all respondents who volunteered they were on medication/anti-depressants (in either the dysphoric mood or the anhedonia section) as probable cases for major depression. (See mentalhealth.samhsa.gov/publications/allpubs/SMA04-3938/Chapter08.asp.) Again, using this last criterion (that all persons taking anti-depressants are probable cases for major depression) means that more people will be classified as probable cases for major depression with the NHIS survey instrument than with the CIDI-SF instrument.