Depression Test (PHQ-9)
A clinically validated self-assessment tool based on the PHQ-9 standard. Features score tracking, severity visualization, and coping strategies.
About
Clinical accuracy in mental health screening requires adherence to validated standards. This tool utilizes the Patient Health Questionnaire-9 (PHQ-9), the gold standard for monitoring depression severity in primary care settings. It evaluates the frequency of depressive symptoms over the preceding two weeks. Unlike generic quizzes, this implementation focuses on precise scoring metrics and longitudinal tracking via local storage, enabling users to monitor fluctuations in mood over time without transmitting sensitive data to external servers. It is designed for preliminary screening and monitoring, not for clinical diagnosis.
Formulas
The PHQ-9 scoring algorithm sums the integer value of 9 responses, where values range from 0 (Not at all) to 3 (Nearly every day). The total score S determines the severity classification.
Where qi is the user response integer for the i-th question.
Reference Data
| Score Range | Depression Severity | Clinical Action (Standard Protocol) |
|---|---|---|
| 0 - 4 | None-minimal | None |
| 5 - 9 | Mild | Watchful waiting; repeat at follow-up |
| 10 - 14 | Moderate | Treatment plan consideration |
| 15 - 19 | Moderately Severe | Active treatment with pharmacotherapy or psychotherapy |
| 20 - 27 | Severe | Immediate initiation of treatment; referral to specialist |