One-year prevalence of subthreshold and threshold DSM-IV generalized anxiety disorder in a nationally representative sample
Depression and Anxiety
http://www.ncbi.nlm.nih.gov/pubmed/?term=One-year%20prevalence%20of%20subthreshold%20and%20threshold%20DSM-IV%20generalized%20anxiety%20disorder%20in%20a%20nationally%20representative%20sample.