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

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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

FDA Panel

FDA Panel

FDA Panel Discusses Safety, Use of SSRIs During Pregnancy

08/06/2025

Kate Young

In an FDA panel held on July 21, 2025, experts discussed the nuances of risk-benefit counseling and stronger warnings for selective serotonin reuptake inhibitors (SSRIs) to ensure informed consent among...

08/06/2025

PUPC Conference Coverage

PUPC Conference Coverage

Evidence-Based Strategies Show Strong Outcomes in Treating Adolescent Mental Health Post-Pandemic

07/18/2025

Kate Young

Amid rising rates of adolescent mental health issues, especially following the COVID-19 pandemic, primary care providers are uniquely positioned to identify and treat conditions like depression and anxiety...

07/18/2025

Research Summary

Low Prevalence of Depression in Children from 2004 to 2019

01/18/2024

Jessica Ganga

Researchers evaluated the prevalence of depression disorders in pediatric patients to determine if there is a mental health impact on this age group.

01/18/2024

April 2026

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April 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