Depression is a broad and heterogeneous condition. Commonly used diagnostic manuals include the World Health Organization’s ICD-11 classification system and the American Psychiatric Association’s DSM-5-TR system. Depression often has a remitting and relapsing course, and symptoms may persist between episodes. This slide deck explores fundamental concepts and definitions related to depression, including signs and symptoms, differential diagnosis, and commonly used screening and rating instruments.

This slide deck was developed by Professor Dr. Anthony Cleare, Professor of Psychopharmacology & Affective Disorders, Institute of Psychiatry, Psychology & Neuroscience, Department of Psychological Medicine, King’s College London, United Kingdom; and Professor Dr. Lakshmi Yatham, Department of Psychiatry, University of British Columbia, Canada, in collaboration with Cambridge (a division of Prime, Cambridge, UK).

Index for
slide deck

Major depressive disorder (MDD) - Definitions and Diagnosis

Major depressive disorder (MDD) - Definitions and Diagnosis
Major depressive disorder (MDD) - Definitions and Diagnosis
file_download Download slide in HQ

Definition of major depressive disorder

Definition of major depressive disorder
Definition of major depressive disorder
file_download Download slide in HQ
Depression
Depression

Depression can be defined based on the World Health Organization’s ICD-11 classification system or the American Psychiatric Association’s DSM-5-TR system.

References:
1. National Institute for Health and Care Excellence CG222. Depression in adults: recognition and manag…

file_download Download slide in HQ
Symptoms of depression
Symptoms of depression

The many symptoms of depression are varied, and can include emotional, cognitive, and physical symptoms that cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.1,2

References:
1. American Psychiatric Asso…

file_download Download slide in HQ
The impact of the symptoms of depression on patients
The impact of the symptoms of depression on patients

As outlined on the slide, the various symptoms of depression can negatively impact a patient’s functioning, including in the areas of work or school, family life, and social life.1,2

References:
1. American Psychiatric Association. Diagnostic and Statistical Manual of M…

file_download Download slide in HQ
MDD symptoms in DSM-5-TR
MDD symptoms in DSM-5-TR

The American Psychiatric Association (APA) describes nine depressive symptoms for diagnostic purposes, as outlined on the slide.1 At least five of these symptoms, at least one of which is ‘depressed mood’ or ‘loss of interest or pleasure’ are required during the same two-…

file_download Download slide in HQ
DSM-5-TR criteria for MDD
DSM-5-TR criteria for MDD

The Diagnostic and Statistical Manual (DSM) of Mental Disorders is published by the American Psychiatric Association and provides standard criteria for the classification of mental disorders. It is now in its fifth edition text revision, DSM-5-TR, which was published in 2…

file_download Download slide in HQ
The Montgomery–Åsberg Depression Rating Scale
The Montgomery–Åsberg Depression Rating Scale

The Montgomery–Åsberg Depression Rating Scale (MADRS), which was designed to be sensitive to the effects of antidepressants, includes ten depressive symptoms.1 Some studies evaluating antidepressant effect have used the six-item MADRS subscale, which includes only the fol…

file_download Download slide in HQ
Definitions of clinical course and treatment outcomes I
Definitions of clinical course and treatment outcomes I

MDD is a chronic disorder, most frequently characterised by relapses and recurrences.2 Relapse can be defined as an episode of MDD that occurs within 6 months of response or remission;2,3 theoretically, relapse signifies the return of a major depressive episode, rather …

file_download Download slide in HQ
MDD is a complex, often recurrent and remitting disorder1
MDD is a complex, often recurrent and remitting disorder1

Long-term treatment of depression with antidepressants benefits many patients by (1) reducing the likelihood of relapse or recurrence and (2) increasing the amount of time spent asymptomatic between episodes.3-5

Discontinuing antidepressant treatment in the acute phase be…

file_download Download slide in HQ
Definitions of symptoms and signs
Definitions of symptoms and signs

As outlined on the slide, symptoms are apparent to the patient, whereas signs are not always.1 Diagnostic criteria for major depressive disorder cover many of the signs and symptoms of which a clinician should be aware.2,3

References:
1. King LS. Signs and symptoms. JAMA …

file_download Download slide in HQ
Definitions of epidemiological terms
Definitions of epidemiological terms

The slide explains the difference between prevalence and incidence as key epidemiological terms. While prevalence is the proportion of persons with condition, in a given population, at a designated time, the incidence describes the number of people newly developing a cond…

file_download Download slide in HQ
Definitions of burden of disease and key epidemiological terms
Definitions of burden of disease and key epidemiological terms

This slide gives definitions for key epidemiological terms used in studies to quantify the burden of a disease. Term defined are the Burden of disease (BoD), Quality adjusted life years (QALYs), Years of life lost (YLLs), Years lived with disability (YLDs), Disability adj…

file_download Download slide in HQ
Definitions of clinical course and treatment outcomes II
Definitions of clinical course and treatment outcomes II

The terms ‘response’ and ‘remission’ have been used to mean different things in psychiatric research; the most commonly used meanings of these terms in studies of treatment outcomes in people with major depression disorder are given on the slide.1,2

References:
1.Nieren…

file_download Download slide in HQ

Related content

grid_view Slide Deck Treatment principles
Major depressive disorder (MDD) – Treatment principles

This slide deck covers the treatment principles of Major Depressive Disorder (MDD).

12.06.2025 Depression
grid_view Slide Deck
Major depressive disorder (MDD) – Course, natural history and prognosis

This slide deck covers the course, natural history, and prognosis of Major depressive disorder (MDD)

27.05.2025 Depression
grid_view Slide Deck MDD - Epidemiology and burden
Major depressive disorder (MDD) – Epidemiology and burden

This slide deck summarizes the global patterns and societal impact of Major Depressive Disorder (MDD). It covers prevalence trends by sex, age, time, and location, as well as the effects of the COVID-19 pandemic.

23.05.2025 Depression