Validation of the Tunisian version of the Patient Health Questionnaire -9 (PHQ- 9) for Depression screening.

Background: Depression is a major burden for the health-care system worldwide. It is important to use standardized and easily applicable tools for large-scale population screening to improve the early detection of depression. The PHQ-9 has been recommended as the best available screening and case-finding instrument based on its brevity and ability to inform the clinicians on both depression severity and diagnostic criteria.