Data come from the 5001 respondents who participated in the 1990–2 National Comorbidity Survey (NCS)28 and the 2001–03 NCS Follow-up Survey (NCS-2).29 The NCS28 was a nationally representative US survey of 8098 respondents ages 15–54 with a response rate of 82.4%. Interviews were conducted by professional survey interviewers and administered in two parts. Part I, which included the core diagnostic interview, was administered to all respondents. Part II, which included additional disorders and risk factors, was administered to a probability sub-sample of 5877 respondents including all respondents ages 15–24, all others with any lifetime DSM-III-R disorder assessed in Part I, and a random sub-sample of remaining Part I respondents. The Part II sample was weighted to adjust for differential probabilities of selection and for non-response bias. The non-response adjustment weight was based on the results of a brief screening survey carried out in a representative sub-sample of initial survey non-respondents. Further details about the NCS design and weighting are reported elsewhere.28
