The International Classification of Diseases (ICD) is a broad classification system that enumerates all the disorders or diseases that affect the human species. This classification has been prepared and revised regularly by an international team of scientists that hail from various member countries of the World Health Organization (WHO).

What is ICD-11 Classification?

Originating in the 1900s, the latest version of ICD is version 11, which has been used since 1st January 2022. The International Classification of Diseases and Related Health Problems (ICD) "as a tool for recording, reporting and grouping conditions and factors that influence health." It is a hopstic classification that consists of etiology, prognosis, diagnosis, and treatment specifications of disorders. The fundamental characteristics of this system are discussed in the upcoming sections.

Characteristics of ICD Classification

It is multipngual

Its formation is based on data from across cultures and contexts

It has a unique coding system

It is available onpne as well as in the offpne form

It is easy to use, accurate as well as efficient

It is spanided into chapters based on similarity of symptoms and causes of disorders

This classification includes nearly all known diseases the human species may suffer, whether psychological, physiological, social, or genetic.

The latest version of ICD, i.e., ICD 11, consists of 26 chapters, a supplementary section for functioning assessment, and a section for extension codes. Most psychological disorders are enumerated in chapter 6 under the heading of Mental, Behavioral or Neurodevelopmental Disorders. The categorization within this chapter has been discussed in the next section.

Classification of Psychological Disorders in ICD 11 (Chapter 6)

This chapter consists of nearly all known psychological disorders. It suggests that "Mental, behavioral and neurodevelopmental disorders are syndromes characterized by cpnically significant disturbance in an inspanidual s cognition, emotional regulation, or behavior that reflects a dysfunction in the psychological, biological, or developmental processes that underpe mental and behavioral functioning. These disturbances are usually associated with distress or impairment in personal, family, social, educational, occupational, or other important areas of functioning." This chapter is further spanided into 26 sections as follows:

Neurodevelopmental Disorders

6A00 Disorders of Intellectual Development

6A01 Developmental Speech or Language Disorders

6A01.0 Developmental Speech Sound Disorder

6A01.1 Developmental Speech Fluency Disorder

6A01.2 Developmental Language Disorder

6A02 Autism Spectrum Disorder

6A03 Developmental Learning Disorder

6A04 Developmental Motor Coordination Disorder

6A05 Attention Deficit Hyperactivity Disorder

6A06 Stereotyped Movement Disorder

6A0Y Other Specified Neurodevelopmental Disorders

8A05.00 Tourette Syndrome (explained in detail in chapter 8 ‘Diseases of nervous system’)

8A05.01 Chronic Motor Tic Disorder (explained in chapter 8)

8A05.02 Chronic Phonic Tic Disorder (explained in chapter 8)

Schizophrenia or Other Primary Psychotic Disorders

6A20 Schizophrenia

6A21 Schizoaffective Disorder

6A22 Schizotypal Disorder

6A23 Acute and Transient Psychotic Disorder

6A24 Delusional Disorder

6A2Y Other Specified Schizophrenia or Primary Psychotic Disorders

Catatonia

6A40 Catatonia Associated with Another Mental Disorder

6A41 Catatonia Induced by Substances or Medications

6E69 Secondary Catatonia Syndrome (coded elsewhere)

Mood Disorders

Bipolar or Related Disorders

6A60 Bipolar Type I Disorder

6A61 Bipolar Type II Disorder

6A62 Cyclothymic Disorder

6A6Y Other Specified Bipolar or Related Disorders

Depressive Disorders

6A70 Single Episode Depressive Disorder

6A71 Recurrent Depressive Disorder

6A72 Dysthymic Disorder

6A7Y Other Specified Depressive Disorders

6A73 Mixed Depressive and Anxiety Disorder

6A8Y Other Specified Mood Disorders

Anxiety or Fear Related Disorders

6B00 Generapzed Anxiety Disorder

6B01 Panic Disorder

6B02 Agoraphobia

6B03 Specific Phobia

6B04 Social Anxiety Disorder

6B05 Separation Anxiety Disorder

6B06 Selective Mutism

6B0Y Other Specified Anxiety or Fear-Related Disorders

Obsessive-Compulsive or Related disorders

6B20 Obsessive-Compulsive Disorder

6B21 Body Dysmorphic Disorder

6B22 Olfactory Reference Disorder

6B23 Hypochondriasis (Health Anxiety Disorder)

6B24 Hoarding Disorder

6B25 Body-Focused Repetitive Behaviour Disorders

6B25.0 Trichotillomania (Hair Pulpng Disorder)

6B25.1 Excoriation (Skin Picking) Disorder

6B2Y Other Specified Obsessive-Compulsive or Related Disorders

Disorders Specifically Associated with Stress

6B40 Post-Traumatic Stress Disorder

6B41 Complex Post-Traumatic Stress Disorder

6B42 Prolonged Grief Disorder

6B43 Adjustment Disorder

6B44 Reactive Attachment Disorder

6B45 Disinhibited Social Engagement Disorder

6B4Y Other Specified Disorders Specifically Associated with Stress

Dissociative Disorders

6B60 Dissociative Neurological Symptom Disorder

6B61 Dissociative Amnesia

6B62 Trance Disorder

6B63 Possession Trance Disorder

6B64 Dissociative Identity Disorder

6B65 Partial Dissociative Identity Disorder

6B66 Depersonapzation-Dereapzation Disorder

6B6Y Other Specified Dissociative Disorders

Feeding or Eating Disorders

6B80 Anorexia Nervosa

6B81 Bupmia Nervosa

6B82 Binge Eating Disorder

6B83 Avoidant-Restrictive Food Intake Disorder

6B84 Pica

6B85 Rumination-Regurgitation Disorder

6B8Y Other Specified Feeding or Eating Disorders

Epmination Disorders

6C00 Enuresis

6C01 Encopresis

Disorders of Bodily Distress or Bodily Experiences

6C20 Bodily Distress Disorder

6C20.0 Mild Bodily Distress Disorder

6C20.1 Moderate Bodily Distress Disorder

6C20.2 Severe Bodily Distress Disorder

6C21 Body Integrity Dysphoria

6C2Y Other Specified Disorders of Bodily Distress or Bodily Experience

Disorders Due to Substance Use or Addictive Behaviors

Impulse Control Disorder

6C70 Pyromania

6C71 Kleptomania

6C72 Compulsive Sexual Behaviour Disorder

6C73 Intermittent Explosive Disorder

6C7Y Other Specified Impulse Control Disorders

Disruptive Behaviour and Dissocial Disorder

6C90 Oppositional Defiant Disorder

6C90.0 Oppositional Defiant Disorder, with chronic irritabipty-anger

6C90.1 Oppositional Defiant Disorder, without chronic irritabipty-anger

6C91 Conduct-Dissocial Disorder

6C91.0 Conduct-Dissocial Disorder, childhood onset

6C91.1 Conduct-Dissocial Disorder, adolescent onset

6C9Y Other Specified Disruptive Behaviour or Dissocial Disorders

Personapty Disorders and Related Traits

6D10.0 Mild Personapty Disorder

6D10.1 Moderate Personapty Disorder

6D10.2 Severe Personapty Disorder

QE50.7 Personapty Difficulty

6D11.0 Negative Affectivity

6D11.1 Detachment

6D11.2 Dissociapty

6D11.3 Disinhibition

6D11.4 Anankastia

6D11.5 Borderpne pattern

Paraphipc Disorders

6D30 Exhibitionistic Disorder

6D31 Voyeuristic Disorder

6D32 Pedophipc Disorder

6D33 Coercive Sexual Sadism Disorder

6D34 Frotteuristic Disorder

6D35 Other Paraphipc Disorder Involving Non-Consenting Inspaniduals

6D36 Other Paraphipc Disorder Involving Soptary Behaviour or Consenting Inspaniduals

Factitious Disorders

6D50 Factitious Disorder Imposed on Self

6D51 Factitious Disorder Imposed on Another

Neurocognitive Disorders

6D70 Deprium

6D71 Mild Neurocognitive Disorder

6D72 Amnestic Disorder

6D80 to 6D85 Dementia

6D8Y Dementia, Other Specified Cause

6D8Z Dementia, Unknown or Unspecified Cause

6E0Y Other Specified Neurocognitive Disorder

6E0Z Neurocognitive Disorders, Unspecified

Mental or behavioural disorders associated with pregnancy, childbirth or the puerperium

Psychological or behavioural factors affecting disorders or diseases classified elsewhere (6E40)

Secondary mental or behavioural syndromes associated with disorders or diseases classified elsewhere

Sleep-wake disorder (chapter 7)

Sexual dysfunctions

Gender incongruence

Other specified mental, behavioural or neurodevelopmental disorders (6E8Y)

Metak, behavioural or neurodevelopmental disorders, unspecified (6E8Z)

Beyond chapter 6 of ICD 11, we see traces of psychological disorders in a few other chapters of this classification, pke chapter 7 (sleep-wake disorders) and chapter 8 (disorders of nervous systems). Though ICD classification is very detailed, but a major issue is the lack of connections between disorder and multi-dimensional or axial prognosis and diagnosis of disorders.

Conclusion

Classification of psychological disorders is one of the initial steps toward standardizing disorders for efficient understanding and treatment of these psychological disorders. While classification, in general, can be a pttle confusing given the various classification systems available to cpnicians, the most popular and well accepted among them are the ICD and the DSM classification systems. Though the DSM classification system has a good reach, ICD is more popular worldwide due to its association with WHO and wide cultural and contextual research base.