Update in International Classification of Diseases-11: Changes in Mood Disorders

Aworshim Muivah¹, RK L Singh², Rajkumari Lorinda³

^1,2Department of Psychiatry, Regional Institute of Medical Sciences, Imphal, Manipur, India

³Department of Psychiatry, Institute of Medical Sciences and SUM Hospital, Siksha “O” Anusandhan, Bhubaneswar, Odisha, India

Corresponding Author: Aworshim Muivah, Department of Psychiatry, Regional Institute of Medical Sciences, Imphal, Manipur, India, e-mail: onlineifp@gmail.com

Received on: 26 September 2024; Accepted on: 12 November 2024; Published on: 16 November 2024

ABSTRACT

This article provides a brief overview of the changes in the classification categories in mood disorders, viz. bipolar disorders and depressive disorders, from the International Classification of Diseases (ICD), ICD-10 to ICD-11 and its comparison with the Diagnostic and Statistical Manual of Mental Disorders, DSM-5. ICD-11 was implemented in January 2022, and as of February 2023, the World Health Organization (WHO) reported that 64 countries were in various stages of implementing the ICD-11.

How to cite this article: Muivah A, Singh RL, Lorinda R. Update in International Classification of Diseases-11: Changes in Mood Disorders. East J Psychiatry 2024;24(2):36-38.

Source of support: Nil

Conflict of interest: None

Keywords: Bipolar disorders, Depressive disorders, Diagnostic statistical manual of mental disorders, International classification of diseases, Mood disorders.

INTRODUCTION

The World Health Organization’s (WHOs) 11th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11) developed the chapter on Mental, Behavioral, or Neurodevelopmental Disorders (MBND). As far as the classification of mental health disorders is concerned, this is the largest process. Moreover, in history, it is the most participative one too. This process aims to achieve global applicability. If global applicability is one of the three aims, then the other two are scientific validity and clinical utility.¹^,²

The ICD-11 MBND has a volume, the Clinical Description and Diagnostic Requirements (CDDR). This is the result of work done in collaboration for more than a decade. During the overall culmination of ICD-11 only, and within its context throughout the building up, it was carried out.³

The introduction of ICD-11, which is being implemented in 64 WHO member countries, has seen changes in the diagnostic categories of various disorders, including mood disorders, viz. bipolar disorders and depressive disorders. Compared to the tenth revision (ICD-10), mood disorders have a simpler structure. It is easy to use too. Although simple, the description of individual diagnoses is elaborate and precise. Moreover, it is at par with what the current knowledge base says about the various mood disorders.⁴ It is true that we still lack laboratory findings to corroborate clinical features. As a result, the signs and symptoms determine the psychiatric diagnosis, along with the disorders’ courses.⁵

HISTORICAL PERSPECTIVE OF BIPOLAR DISORDER (MANIA AND DEPRESSION)

Schizophrenia was earlier known as dementia praecox. Emil Kraepelin was the first to tell us that there is an entity separate from dementia praecox. It was the year 1895. What this German psychiatrist called the new diagnosis was manic depression. Later on, it became today’s bipolar disorder.

In fact, tracing the history of mental state-related nosological discussions, we do find mentions of mania and depression as early as the second century. The Emperor Trajan reigned in Rome during 98–177 A.D. His physician was Soranus of Ephedrus. We find his writings on mania and melancholia. Both of them were considered as diseases that were separate from each other. Different etiologies were attributed to them. At the same time, he acknowledged: “Many others consider melancholia a form of the disease of mania.” Philippe Pinel (1745–1826) wrote his “Traité médico-philosophique sur l’aliénation mentale, ou la manie” in 1801. This work is mostly about mania. Pinel stressed the fact that mania has a “periodic or intermittent” course. He did not elaborate much on the relation of mania with other states of mental health (Table 1).⁶

**Table 1:** Kraepelin’s categories of abnormal mood states
Manic states	Hypomania Acute mania Delusional mania (“excitement is not usually severe”) Delirious mania (“accompanied by & clouding of consciousness”)
Depressive states	Melancholia simplex (“psychic inhibition without hallucinations or... delusions”) Stupor Melancholia gravis (psychotic depression) Paranoid melancholia Fantastic melancholia (“abundant” hallucinations and “multifarious” delusions) Delirious melancholia (“profound... clouding of consciousness”)
Mixed states	Depressive or anxious mania (“mood is anxiously despairing”) Excited depression (“extraordinary poverty of thought but... great restlessness”) Mania with poverty of thought (“unproductive mania with poverty of thought”) Manic stupor (“cheerful mood” but “inaccessible”) Depression with flight ideas Inhibited mania Acute delirious mania (“raving mania”) Grumbling mania (“exalted self-consciousness” but “dissatisfied, insufferable”) Partial features
Fundamental states	Depressive temperament Manic temperament Irritable temperament Cyclothymic temperament

From: Emil Kraepelin (1976)

CHANGES MADE TO THE CATEGORY OF DEPRESSIVE DISORDERS

To rectify some of the lacunae in ICD-10, the depressive disorders’ section in ICD-11 begins with the mention of the guidelines to make a diagnosis. The pertinent differences are:

The cluster of symptoms that are specific for depression is unique in ICD-11 revision-affective cluster, neurovegetative cluster, and cognitive-behavioral cluster.
From the list of essential features, reduced energy and fatigue are omitted and they are now part of the “neurovegetative” cluster.
Another difference from ICD-10 is that now five symptoms are required for the threshold and one of those five symptoms has to be from the “affective cluster.”⁸
An essential feature is impaired role function. The relation of functional decline with the severity of depression is evidence-based. Moreover, diagnosing depression with sole reliance on symptoms is a fallacy that is well-known. Though impairment of role functioning was included in ICD-10, it was not an essential criterion.
In a deviance from the ICD-10, in ICD-11, grading severity no longer depends upon requirement of the number of symptoms. In contrast what is now more apparent is the severity of functional impairment and its impact.
There is an enlargement in describing psychotic symptoms’ subtype. Catatonia is nor more a part here in the ICD-11 revision.
“Moderate depressive episode with psychotic symptoms” is a new subtype.
From depression diagnosis, “bereavement exclusion” (BE) criterion is removed leading to controversy and debate.
Single as well as recurrent depression have qualifiers like remission, melancholia, with seasonal onset, etc (Tables 2 and 3).⁴

**Table 2:** This is a brief comparison between ICD-10 and ICD-11 on depressive disorders
ICD-10	ICD-11
Depressed mood, loss of interest and enjoyment, and easy fatiguability are regarded as the typical core symptoms which must be present for a definite diagnosis and also for severity	The core criteria are depressive mood (e.g., sad mood, irritable, empty) or loss pleasure accompanied by other cognitive, behavioral or neurovegetative symptoms
In defining the severity, that is, mild, moderate and severe; two, three, and four other symptoms should be present. Degree of sociooccupational impairment is not considered for severity	Degree of sociooccupational impairment determines the severity. An individual with mild severity typically has some, but not considerable difficulty; with moderate severity has considerable difficulty; with severe symptoms is unable to function in personal, family, social, educational, occupational, or other domains
Psychotic symptoms are present only in severe depression	Psychotic symptoms can be present even in moderate depression
There is no specifier for unspecified severity	Different specifier for unspecified severity
There is no different specifier for partial and full remission	There is a different specifier for partial and full remission
Mixed anxiety and depressive disorder was included under “neurotic, stress–related, and somatoform disorders (F41.2)”	Mixed depressive and anxiety disorders is included under mood disorders (6A73)
No specifiers for prominent anxiety symptoms, panic attacks in mood episodes, etc.	Different specifiers for prominent anxiety symptoms, panic attacks in mood episodes, with melancholia, with seasonal pattern and rapid cycling

**Table 3:** The comparison of changes between DSM-5 and ICD-11 are as follows
DSM-5	ICD-11
Disruptive mood dysregulation (DMDD) is described under depressive disorders	DMDD is described under disruptive behaviors or dissocial disorders
Premenstrual dysphoric disorder is described under depressive disorders	Premenstrual disturbances which include significant mood symptoms are described in Chapter 16 of the ICD-11: diseases of the genitourinary system
Persistent depressive disorder (dysthymia) is described as the same	Recurrent depressive disorder and dysthymic disorder are described separately

CHANGES INTO THE BIPOLAR CATEGORY

The changes made in ICD-11 to bipolar disorder are more elaborate and precise. The broad changes made are:

Normal mood variations are different from symptoms that typify mania. Mood changes are persistent whether in mania or hypomania manifested by “euphoria, irritability, expansiveness, and lability.” Simultaneously activity or energy changes are present.
Variation from ICD-10 is increased activity/energy getting included. This is evidence-based for both mania and hypomania.⁸
Pharmacological treatment’s effect is an additional feature now. It is considered a positive change.⁹
International Classification of Diseases-11 says contrasting ICD-10 that for bipolar I disorder one episode of mania or mixed suffices.
That sets ICD-11 apart from ICD-10 is bipolar II disorder’s inclusion.⁴
Cyclothymia currently attains a board and clear concept. Variations may be subthreshold but persistent with impairment in function (Table 4).⁴

**Table 4:** The comparison between ICD-10 and ICD-11 on bipolar disorder are as follows
ICD-10	ICD-11
Bipolar affective disorder	Replaced by bipolar or related disorders
Atleast two diagnosis of mania are required for a diagnosis of bipolar disorder	Occurrence of one or more manic or mixed episode is sufficient for diagnosis
Single episode is defined separately: manic episode; hypomania	No separate diagnosis for a single episode. One episode is enough for a diagnosis of bipolar disorder
Bipolar II disorder is included in “other bipolar affective disorder”	A separate diagnostic criteria is given for bipolar type II disorder as in DSM-5
Though there are different specifiers for bipolar affective disorder, current episode mild depression; moderate depression and severe depression, there is no different specifiers for “unspecified severity”	A new specifier is introduced, that is bipolar type I disorder; current episode depressive, unspecified variety (6A60.8) and also for bipolar type II disorder, current episode depressive, and unspecified severity (6A61.8)
There is a different specifier for bipolar affective disorder, currently in remission, but it is not mentioned whether it’s a partial or a full remission	There is a different specifier for partial and full remission
Patients with bipolar affective disorder may have anxiety symptoms, panic attacks, or symptoms with a seasonal pattern	There are different specifiers for both bipolar types I and II disorder for patients with prominent anxiety symptoms (6A80.0); with panic attacks (6A80.1): current depressive episode persistent (6A80.2); current depressive episode melancholia (6A80.3); with seasonal pattern of onset (6A80.4); and with rapid cycling (6A80.5)

CONCLUSION

International Classification of Diseases-11 has introduced many changes in mood disorders, which will be easier to apply than ICD-10. The different specifiers and consideration of boundaries are some new features introduced in ICD-11 that will be of great use and help. These boundaries include those ”with normality, other disorders which share presenting (similar) features, culture-related features, sex- and gender-related features, boundaries with other disorders and conditions (differential diagnosis).” The country has yet to use ICD-11 on a full scale; it is high time we start implementing ICD-11.

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