Kroenke, K., Spitzer, R.L., & Williams, J.B. (2001). The PHQ-9: Validity of a brief depression screening measure. Journal of General Internal Medicine, 16, 606-613.
Kroenke, K., Spitzer, R.L., & Williams, J.B. (2001). The PHQ-9: Validity of a brief depression screening measure. Journal of General Internal Medicine, 16, 606-613.