Major Depressive Disorder

Disease State Hub

Commentary

Major Depressive Disorder Snapshot

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For a period of at least 2 weeks, an individual maintains a depressed mood, which may involve feelings of guilt or worthlessness, lack of energy, poor concentration, appetite changes, agitation, sleep disturbances, or suicidal thoughts.

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clinical psychologists, psychiatrists, primary care physicians, emergency medicine, social workers

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One must have at least 5 symptoms from this list: depressed mood, inability to experience pleasure, feelings of guilt or worthlessness, lack of energy, poor concentration, appetite changes, agitation, sleep disturbances, or suicidal thoughts

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(continued) From that list, one of the symptoms must be a depressed mood or inability to experience pleasure in order to be diagnosed with MDD.

Ref: https://www.ncbi.nlm.nih.gov/books/NBK559078/

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The Patient Health Questionnaire-9 (PHQ-9): Used to quantify severity and assist in diagnosis of depression symptoms. PHQ-9 scores each of the DSM criteria of MDD as “0” (not at all) to “3” (nearly every day), providing a 0-27 severity score.

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Hamilton Rating Scale for Depression (HAM-D): clinician-administered depression rating scale commonly used to measure depression in adults. Of the 21 items on the scale, only the first 17 are used for scoring.

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(continued) Other tests include: Beck Depression Inventory, Zung Self-Rating Depression Scale, Geriatric Depression Scale, Center for Epidemiologic Studies-Depression Scale

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In 2021, an estimated 21 million adults in the United States had at least one major depressive episode, representing an estimated 8.3% of all U.S. adults.

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The US Preventive Services Task Force recommends that all adults—including those pregnant and postpartum—be screened for depression.

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The percentage of female high school students who experienced persistent feelings of sadness or hopelessness in 2021 was 57%, a record level and double the rate of males.

Research Summaries

Research Summary

Research Summary

Collaborative Care for Depression in Primary Care: Meta-Analysis Identifies Most Effective Treatment Components

05/08/2026

Anthony Calabro, MA

An individual participant data meta-analysis clarifies which elements of collaborative care most effectively reduce depressive symptoms in primary care, informing implementation strategies for clinicians...

05/08/2026

Research Summary

Research Summary

Measurement-Based Care Speeds Depression Response, Remission in Randomized Trial

05/06/2026

Kate Young

A randomized clinical trial in Pakistan evaluated whether structured, measurement-based care could accelerate antidepressant response and remission in adults with major depressive disorder compared with...

05/06/2026

FDA Approval

FDA Approval

Lumateperone (Caplyta) Gains FDA Approval for Relapse Prevention in Schizophrenia

04/30/2026

Anthony Calabro, MA

The FDA has approved a supplemental indication for lumateperone to reduce relapse risk in adults with schizophrenia based on phase 3 randomized withdrawal data.

04/30/2026

Research Summary

Woman with clipboard holding someone's hands

Research Summary

Danish Primary Care Trials Find Collaborative Care Improves Long-Term Depression Outcomes Versus Consultation Liaison

03/25/2026

Kate Young

In two pragmatic randomized trials conducted in the Capital Region of Denmark, investigators compared collaborative care with consultation liaison in general practice to assess whether greater involvement...

03/25/2026

Research Summary

Research Summary

Soft Drink Intake Linked to MDD Diagnosis and Severity, Partly Mediated by Eggerthella in Women

10/15/2025

Kate Young

Recent research found that soft drink consumption may be linked to major depressive disorder diagnosis and increased depressive symptom severity, with significant associations observed only among women. ...

10/15/2025

May 2026

Current Issue

May 2026

Sources:

https://www.ncbi.nlm.nih.gov/books/NBK559078/
https://www.nimh.nih.gov/health/statistics/major-depression
Kroenke K, Spitzer RL, Williams JB. The PHQ-9: validity of a brief depression severity measure. J Gen Intern Med. 2001 Sep;16(9):606-13.
https://www.med.upenn.edu/cbti/assets/user-content/documents/Hamilton%20Rating%20Scale%20for%20Depression%20(HAM-D).pdf
Centers for Disease Control and Prevention. Youth behavior risk survey: data summary and trends report. Accessed March 31, 2023. https://www.cdc.gov/healthyyouth/data/yrbs/yrbs_data_summary_and_trends.htm