ICD-11 Chapter 06: Mental, Behavioral and Neurodevelopmental Disorders
What is this Chapter?
Chapter 06 of ICD-11 encompasses all mental, behavioral, and neurodevelopmental disorders, representing one of the most extensive and clinically relevant sections of the classification. This chapter provides diagnostic codes for conditions that affect cognition, emotion, behavior, and neurological development, from childhood through adulthood. It includes neurodevelopmental disorders that manifest early through acquired conditions such as dementias, psychotic disorders, mood disorders, anxiety disorders, stress-related disorders, eating disorders, sleep disorders, and substance use disorders.
The importance of this chapter transcends psychiatric practice, being fundamental for neurology, pediatrics, family medicine, geriatrics, and various other specialties. With the transition from ICD-10 to ICD-11, there was significant modernization of diagnostic criteria, better alignment with current scientific evidence, and greater clinical utility. The chapter was restructured to better reflect contemporary understanding of mental disorders, eliminating stigmatizing terminology and incorporating dimensional approaches when appropriate.
Chapter Structure
Chapter 06 contains more than 30 main categories organized by type of disorder, following a sequence that ranges from neurodevelopmental disorders (which typically manifest in childhood) to neurocognitive disorders and conditions associated with aging. The structure facilitates clinical navigation and reflects groupings based on shared characteristics, etiology, or the life phase in which they typically manifest.
Main Categories
Neurodevelopmental Disorders
This category encompasses conditions that manifest during the developmental period, typically in childhood or early adolescence, characterized by developmental deficits that produce impairments in personal, social, academic, or occupational functioning. It includes disorders of intellectual development, communication, autism spectrum, learning, motor, and attention-deficit/hyperactivity. These disorders frequently coexist and may persist throughout life, requiring continued support approaches.
➡️ [See complete guide on Neurodevelopmental Disorders]
6A00: Intellectual Developmental Disorders
Characterized by significant limitations in intellectual functioning and adaptive behavior, manifesting during the developmental period. ICD-11 classifies by severity levels (mild, moderate, severe, profound) based on adaptive functioning, not just IQ scores. Includes specifiers to indicate whether there is associated behavioral impairment. This dimensional approach allows better planning of support and individualized interventions for each person.
➡️ [See complete guide on Intellectual Developmental Disorders]
6A00.0: Mild Intellectual Developmental Disorder
Represents the least severe level of intellectual impairment, where individuals may develop adequate social and communication skills, with more evident difficulties in complex academic tasks. During childhood, difficulties may not be apparent. In adulthood, many can live independently with appropriate support, maintain employment and relationships. Diagnosis requires comprehensive assessment of adaptive functioning across multiple domains, not just intelligence tests.
➡️ [See complete guide on Mild Intellectual Developmental Disorder]
6A01.0: Speech Sound Developmental Disorder
Characterized by persistent difficulties in the production of speech sounds that interfere with intelligibility or prevent verbal communication. Difficulties are not explained by structural conditions (such as cleft palate), neurological, or hearing problems. It manifests early in development and can significantly impact academic performance and social interaction. Early speech-language pathology intervention is essential to improve prognosis and prevent secondary learning and social difficulties.
➡️ [See complete guide on Speech Sound Developmental Disorder]
6A01.20: Language Developmental Disorder with Impairment of Receptive and Expressive Language
The most severe form of language disorders, where there are significant difficulties in both comprehension (receptive) and production (expressive) of language. Affects vocabulary, grammatical structure, discourse, and functional use of language. These difficulties are substantially below what is expected for age and level of intellectual development, causing significant limitations in communication, social participation, academic performance, and later occupational performance. Requires intensive and prolonged multidisciplinary intervention.
➡️ [See complete guide on Language Developmental Disorder]
6A02.0: Autism Spectrum Disorder without Intellectual Developmental Disorder and with Mild or No Impairment of Functional Language
Represents individuals on the autism spectrum with preserved intelligence and relatively intact language abilities, previously referred to as "Asperger's Syndrome" in ICD-10. They present persistent deficits in social communication and interaction, as well as restricted and repetitive patterns of behavior, but without significant delays in language development or cognition. They may have significant challenges in social reciprocity, nonverbal communication, and relationships, requiring support in complex social contexts.
➡️ [See complete guide on Autism Spectrum Disorder]
6A03.0: Learning Developmental Disorder with Impairment of Reading
Commonly known as dyslexia, characterized by significant and persistent difficulties in learning reading skills, specifically in the accuracy and fluency of word recognition and/or in the ability to decode. It is not explained by intellectual deficits, lack of educational opportunity, or sensory problems. It substantially affects academic performance and everyday activities requiring reading. Early specialized interventions can significantly improve outcomes.
➡️ [See complete guide on Learning Developmental Disorder]
6A05.0: Attention-Deficit/Hyperactivity Disorder, Predominantly Inattentive Presentation
Characterized by a persistent pattern of inattention that interferes with functioning or development, without prominent hyperactivity-impulsivity. Individuals present difficulties in maintaining attention, following instructions, organizing tasks, frequently lose objects, and are easily distracted. This presentation is often underdiagnosed, especially in girls, as symptoms are less disruptive than the hyperactive presentation. It can significantly impact academic, occupational performance, and relationships.
➡️ [See complete guide on Predominantly Inattentive ADHD]
6A06.0: Stereotyped Movement Disorder without Self-Inflicted Injury
Characterized by repetitive motor behaviors, apparently driven and without obvious functional purpose (such as body rocking, hand waving, head banging), that significantly interfere with social or other activities, but do not result in bodily injury. Frequently associated with neurodevelopmental disorders, particularly intellectual development and autism. The distinction of this category is the absence of self-injurious behavior, differentiating it from more severe forms requiring more intensive intervention.
➡️ [See complete guide on Stereotyped Movement Disorder]
6A20: Schizophrenia
Severe psychotic disorder characterized by fundamental distortions and characteristic features of thought and perception, inadequate or blunted affect. Typical symptoms include delusions, hallucinations (especially auditory), disorganized thinking, grossly disorganized or catatonic behavior, and negative symptoms. ICD-11 simplified the classification, eliminating the classical subtypes from ICD-10, focusing on specifiers of current symptoms. Typically chronic course with periods of exacerbation and remission, requiring continued pharmacological and psychosocial treatment.
➡️ [See complete guide on Schizophrenia]
6A40: Mood Disorders
Broad category that includes depressive and bipolar disorders, characterized by significant disturbances of mood, affect, and emotions. Ranges from single depressive episode to bipolar I disorder with multiple manic episodes. ICD-11 provides detailed specifiers for severity, presence of psychotic symptoms, and special features such as prominent anxiety or melancholic symptoms. These disorders are among the leading causes of disability globally, profoundly affecting personal, social, and occupational functioning.
➡️ [See complete guide on Mood Disorders]
6A60: Anxiety or Fear-Related Disorders
Includes generalized anxiety disorder, panic disorder, agoraphobia, specific phobias, social anxiety, and separation anxiety. Characterized by excessive and persistent fear or anxiety, avoidance behaviors, and hypervigilance related to specific objects, situations, or contexts. ICD-11 reorganized this category to better reflect distinct clinical presentations. They are the most prevalent mental disorders, often beginning in childhood or adolescence and, if untreated, becoming chronic.
➡️ [See complete guide on Anxiety Disorders]
6B20: Post-Traumatic Stress Disorder
Develops following exposure to an extremely threatening or horrifying event or situation. Characterized by persistent re-experiencing of the trauma (flashbacks, nightmares), avoidance of thoughts and situations related to the trauma, and persistent sense of current threat. ICD-11 distinguishes PTSD from Complex PTSD, the latter associated with prolonged or repeated trauma with additional disturbances in self-organization. This distinction is clinically important for appropriate therapeutic planning.
➡️ [See complete guide on Post-Traumatic Stress Disorder]
6B40: Obsessive-Compulsive Disorder
Characterized by obsessions (recurrent and persistent, intrusive and unwanted thoughts, impulses, or images) and/or compulsions (repetitive behaviors or mental acts that the person feels compelled to perform). ICD-11 removed OCD from the anxiety category, recognizing it as a distinct entity. Includes specifier for insight (good, poor, absent/delusional beliefs), important for prognosis and therapeutic planning. Often chronic and disabling if not treated appropriately.
➡️ [See complete guide on Obsessive-Compulsive Disorder]
6C40: Substance Use Disorders
Pattern of use of psychoactive substance leading to clinically significant impairment or distress. ICD-11 unified dependence and harmful use in a single category with severity specifiers. Includes disorders related to alcohol, opioids, cannabinoids, sedatives, cocaine, stimulants, hallucinogens, and other substances. Each substance has specific codes for intoxication, withdrawal, and induced disorders. Integrated approach of pharmacological and psychosocial treatment is essential for recovery.
➡️ [See complete guide on Substance Use Disorders]
Most Commonly Used Codes
- 6A70.0 - Mild depressive episode
- 6A71.0 - Recurrent depressive disorder, current episode mild
- 6A70 - Single depressive episode
- 6B00 - Generalized anxiety disorder
- 6A05 - Attention-deficit/hyperactivity disorder
- 6A02 - Autism spectrum disorder
- 6B20 - Post-traumatic stress disorder
- 6A80 - Bipolar disorder type I
- 6C40 - Substance use disorders
- 6A00 - Intellectual developmental disorders
ICD-11 Updates
Chapter 06 underwent substantial revision in the transition from ICD-10 to ICD-11. Among the most significant changes are: elimination of schizophrenia subtypes, reorganization of personality disorders with a dimensional approach, creation of the complex PTSD category, distinction between gaming disorder and risky behavior, removal of "gender identity disorders" from the classification of mental disorders (now in a separate chapter as "gender incongruence"), and simplification of the classification of substance use disorders.
Other innovations include better integration of relevant clinical specifiers, elimination of stigmatizing terminology, alignment with DSM-5 where appropriate (maintaining well-founded differences), and focus on overall clinical utility. The post-coordinated coding system allows greater specificity when needed without overburdening the basic structure, making the chapter more flexible and clinically useful in diverse health care contexts.
Quick Navigation
- [Neurodevelopmental Disorders]
- [Schizophrenia Spectrum Disorders]
- [Mood (Affective) Disorders]
- [Anxiety and Fear-Related Disorders]
- [Disorders Specifically Associated with Stress]
- [Obsessive-Compulsive Disorder]
- [Eating Disorders]
- [Elimination Disorders]
- [Sleep-Wake Disorders]
- [Sexual Dysfunctions]
- [Substance Use Disorders]
- [Impulse Control Disorders]
- [Body-Focused Repetitive Behaviors]
- [Neurocognitive Disorders]
- [Personality Disorders]
Resources
Search tools:
- Search by ICD-11 code
- Search by clinical term
- ICD-10 to ICD-11 converter
- Equivalency tables
Specialty guides:
- General psychiatry
- Child psychiatry
- Neurology
- Family medicine
- Geriatrics
Useful downloads:
- Complete list of Chapter 06 codes
- Main changes ICD-10 vs ICD-11
- Quick coding guide
- Specifiers and qualifiers
This overview provides initial guidance. Consult the specific guides for each category for detailed information on diagnostic criteria, coding, and clinical application.