SO1a-n. As noted above, this is considerably expanded compared to earlier versions of the CIDI in order to detect respondents with generalized social fears.

SO6. Note that we separately date age at onset of fear and age at onset of avoidance.

S08-9. These questions are divided into two sets because the DSM-IV and ICD-10 criteria for number and type of psycho-physiological symptoms differ somewhat. A reader referring to both sets of criteria will quickly pick up the logic of split and of the skip rules.

SO10-14. We found in the baseline NCS clinical reappraisal study that there was sometimes misclassification between social phobia and agoraphobia. These questions are designed to obtain data that will help reduce this confusion by asking about symptoms that are characteristic of agoraphobia.

SO16. This is an example of the many new dimensional questions that have been added to the CIDI for NCS-R in order to help refine our classification of severity thresholds.

SO17. Although this question was designed based on pilot work to be an improvement on the original CIDI question, the NCS-R clinical reappraisal study shows that it failed. Indeed, the validity of the social phobia assessment in NCS-R compared to blind SCID clinical re-interviews is better when we ignore the criterion being evaluated with this question. We're not sure what the difficulty is, but we plan to carry out debriefing interviews both with the clinical interviewers and with respondents in an effort to get to the bottom of this problem and revise this question for future use. At present, users might want to expand, revise, or delete this question, as they prefer.

SO19. This question was added as a "second chance" assessment of recency in each of the three phobia sections based on evidence in pilot studies that respondents often confuse the basic recency question regarding the recency of being afraid of such situation and the recency of actually encountering a social situation that led to a panic attack. We found, consistent with the pilot work, that quite a few respondents who reported in SO18a recency of more than a year ago said that they would very severely fearful if they were exposed to the phobic stimulus today, indicating that they still have the phobia.

SO20. This question was added for a similar reason as SO19. Again, many respondents who reported in SO18 that they no longer had the fear reported in SO20 that they all or most of the time avoided social situations.