Daily Assessment of Symptoms – Anxiety

The Daily Assessment of Symptoms – Anxiety (DAS-A) questionnaire was specifically developed to detect reduction of anxiety symptoms in patients with Generalized Anxiety Disorder (GAD) during the first week of treatment. The original version of the instrument was designed for use in clinical trials assessing new pharmaceutical treatments for patients with GAD. The instrument is able to detect symptom changes within 24 hours of treatment. Currently, this is the only GAD specific tool validated to assess symptom improvement sooner than 1 week following treatment initiation.
References
Further reading

Morlock, R; Williams, V; Cappelleri, J; Harness, J; Fehnel, S; Endicott, J; Feltner, D (2008). "Development and evaluation of the Daily Assessment of Symptoms – Anxiety (DAS-A) scale to evaluate onset of symptom relief in patients with generalized anxiety disorder". Journal of Psychiatric Research 42 (12): 1024–36. doi:10.1016/j.jpsychires
...