PHQ-9 Information — Stats with R

PHQ-9 Depression Screener

Name of the Test: Patient Health Questionnaire-9 (PHQ-9)

Creators: Drs. Robert L. Spitzer, Janet B.W. Williams, Kurt Kroenke, and colleagues, with support from Pfizer Inc.

Purpose: The PHQ-9 is a self-administered diagnostic tool designed to screen, diagnose, monitor, and measure the severity of depression.

What it Tests: The PHQ-9 consists of nine questions, each corresponding to one of the diagnostic criteria for major depressive disorder outlined in the DSM-IV. It assesses the frequency of depression symptoms experienced over the past two weeks, including:

Anhedonia
Depressed mood
Sleep disturbances
Fatigue
Appetite changes
Feelings of worthlessness or excessive guilt
Concentration difficulties
Psychomotor agitation or retardation
Suicidal ideation

Scoring: Each item is scored on a scale from 0 ("not at all") to 3 ("nearly every day"), with the total score ranging from 0 to 27. The severity of depression is classified as follows:

0-4: None to minimal depression
5-9: Mild depression
10-14: Moderate depression
15-19: Moderately severe depression
20-27: Severe depression

Target Population: The PHQ-9 is intended for use in adults, including general medical and mental health patients, as well as the general population. It is widely used in primary care settings, hospitals, and community health centers.

Mental Health Screening Application: We offer this test in our mental health screening application that contains a collection of commonly used screening tests for the convenience of patients and practitioners.