The interview included an extensive demographic section that assessed sex, age, education, marital status, and current household income. Lifetime and 12-month panic disorder, panic attacks, and substance use disorders (including nicotine dependence) were assessed using the World Mental Health Survey Initiative version of the World Health Organization Composite International Diagnostic Interview (WMH-CIDI; Kessler & Ustun, 2004). This is a structured diagnostic interview from which Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM–IV; American Psychiatric Association, 1994) Axis I diagnoses are derived. The CIDI is designed for use by trained, nonclinician interviewers and allows for the generation of diagnoses based on either International Classification of Disease (ICD)-10 or DSM–IV criteria, the latter of which was used in this study. The CIDI has been found to have good validity and reliability for anxiety, mood, and substance use disorders (First, Spitzer, Gibbon, & Williams, 2002). In the present study, the panic psychopathology variables were coded dichotomously (0 = no diagnosis, 1 = diagnosis).
