This depression screener is based on the PHQ-9 (Patient Health Questionnaire-9), a validated clinical instrument developed by Drs. Spitzer, Williams, and Kroenke and widely used in primary care and mental health settings worldwide. The PHQ-9 assesses nine core symptoms of Major Depressive Disorder over a two-week window:
Anhedonia
Depressed Mood
Sleep Disturbance
Fatigue
Appetite Changes
Feelings of Worthlessness
Concentration Difficulty
Psychomotor Changes
Self-Harm Ideation...
