{"doi":"10.1046/j.1525-1497.2001.016009606.x","title":"The PHQ-9","abstract":"<h4>Objective</h4>While considerable attention has focused on improving the detection of depression, assessment of severity is also important in guiding treatment decisions. Therefore, we examined the validity of a brief, new measure of depression severity.<h4>Measurements</h4>The Patient Health Questionnaire (PHQ) is a self-administered version of the PRIME-MD diagnostic instrument for common mental disorders. The PHQ-9 is the depression module, which scores each of the 9 DSM-IV criteria as \"0\" (not at all) to \"3\" (nearly every day). The PHQ-9 was completed by 6,000 patients in 8 primary care clinics and 7 obstetrics-gynecology clinics. Construct validity was assessed using the 20-item Short-Form General Health Survey, self-reported sick days and clinic visits, and symptom-related difficulty. Criterion validity was assessed against an independent structured mental health professional (MHP) interview in a sample of 580 patients.<h4>Results</h4>As PHQ-9 depression severity increased, there was a substantial decrease in functional status on all 6 SF-20 subscales. Also, symptom-related difficulty, sick days, and health care utilization increased. Using the MHP reinterview as the criterion standard, a PHQ-9 score > or =10 had a sensitivity of 88% and a specificity of 88% for major depression. PHQ-9 scores of 5, 10, 15, and 20 represented mild, moderate, moderately severe, and severe depression, respectively. Results were similar in the primary care and obstetrics-gynecology samples.<h4>Conclusion</h4>In addition to making criteria-based diagnoses of depressive disorders, the PHQ-9 is also a reliable and valid measure of depression severity. These characteristics plus its brevity make the PHQ-9 a useful clinical and research tool.","journal":"Journal of General Internal Medicine","year":2001,"id":892,"datarank":20.578746333891928,"base_score":10.675907913990581,"endowment":10.675907913990581,"self_citation_contribution":1.6013861870985875,"citation_network_contribution":18.97736014679334,"self_endowment_contribution":1.6013861870985875,"citer_contribution":18.97736014679334,"corpus_percentile":99.1,"corpus_rank":90,"citation_count":43299,"citer_count":180,"citers_with_citation_signal":180,"citers_with_endowment":180,"datacite_reuse_total":0,"is_dataset":false,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2001-09-01","authors":[{"id":2133,"name":"Robert L. Spitzer","orcid":null,"position":1,"is_corresponding":false},{"id":2135,"name":"Janet B. W. Williams","orcid":"0000-0003-0547-2931","position":2,"is_corresponding":false},{"id":2134,"name":"Kurt Kroenke","orcid":"0000-0002-0114-4669","position":0,"is_corresponding":true}],"reference_count":25,"raw_metadata":{"citation_network_status":"fetched"},"created_at":"2026-03-01T18:20:47.508186Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}