GAD ICD-11 Diagnostic Requirements Explained
Author: Ukrainian Psychological Hub · Published: September 30, 2026 · Editorial Policy
In ICD-11, generalized anxiety disorder (GAD) is coded 6B00 and belongs to the grouping of anxiety or fear-related disorders. The diagnosis is based on a recognizable clinical pattern: marked anxiety expressed as either broad, free-floating apprehensiveness or excessive worry across several areas of everyday life; additional characteristic symptoms; persistence for at least several months on more days than not; clinically significant distress or impairment; and exclusion of better explanations such as another mental disorder, a medical condition, or the effects of a substance or medication. These requirements are set out in the World Health Organization's Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural and Neurodevelopmental Disorders (CDDR).
This page explains those ICD-11 requirements in detail. It is an educational guide to the diagnostic framework, not an online diagnostic instrument. A symptom list, questionnaire score, or similarity between a person's experience and a published description cannot establish GAD by itself.
What does ICD-11 require for a GAD diagnosis?
The shortest accurate summary is that ICD-11 requires a persistent generalized anxiety pattern, not merely the presence of anxiety. The pattern must include the core form of anxiety or worry, characteristic accompanying symptoms, sufficient duration and frequency, meaningful distress or functional impact, and appropriate diagnostic exclusions. The WHO deliberately structures the CDDR as clinical diagnostic requirements rather than a simple checklist in which a reader counts symptoms and arrives at a diagnosis.
For the broader place of GAD within the ICD-11 grouping, see ICD-11 Anxiety Classification: Anxiety or Fear-Related Disorders. For a full overview of symptoms, causes, diagnosis, and treatment, see Generalized Anxiety Disorder: Symptoms, Causes, Diagnosis, and Treatment.
ICD-11 code 6B00 and the diagnostic territory of GAD
ICD-11 places GAD under anxiety or fear-related disorders and assigns it code 6B00. That classification matters because anxiety can occur in many conditions without making those conditions GAD. Panic disorder, agoraphobia, social anxiety disorder, specific phobia, separation anxiety disorder, and selective mutism have their own diagnostic territories within the same grouping. Obsessive-compulsive disorder and post-traumatic stress disorder are classified elsewhere in ICD-11. Anxiety can also occur in depressive disorders, substance-related conditions, medical disorders, and ordinary stress responses.
The practical question is therefore not simply, “Is anxiety present?” It is whether the overall pattern fits GAD better than another explanation and whether the threshold for a clinical disorder is met. This is why a diagnostic assessment examines the form, focus, duration, frequency, context, associated symptoms, functional consequences, medical and substance factors, and possible co-occurring disorders rather than treating anxiety as a single undifferentiated phenomenon.
Requirement 1: marked anxiety as general apprehensiveness or excessive worry
ICD-11 allows two related forms of the core anxiety presentation. One is general apprehensiveness that is not restricted to a particular environmental circumstance, often described as free-floating anxiety. The other is excessive worry about negative events across several aspects of everyday life, such as work, finances, health, or family. A person does not have to articulate one highly specific feared object or situation for GAD to be considered.
This is an important feature of the ICD-11 formulation. The ICD-11 classification review by Kogan and colleagues describes the decision to preserve general apprehensiveness while also making excessive worry across multiple life domains an explicit core feature. This supports recognition of presentations in which a person experiences persistent diffuse apprehension or chronic somatic anxiety but has difficulty giving a detailed verbal account of specific worry content.
What “free-floating anxiety” means
Free-floating anxiety does not mean anxiety with no psychological reality or no context. It describes apprehensiveness that is generalized rather than tightly bound to one object, place, social situation, separation cue, trauma reminder, bodily concern, or anticipated panic attack. Someone may describe a continuing sense that something is wrong or that trouble is likely, even when no single situation explains the anxiety.
That feature helps distinguish GAD from disorders whose fear is organized around a more specific focus. It also prevents an overly narrow diagnostic model in which a person must always be able to name and verbalize multiple explicit worries before the broader clinical pattern can be recognized.
What “excessive worry across several areas of life” means
The worry form of GAD is broad. The content can move among everyday domains: finances, health, work or school, relationships, family responsibilities, mistakes, safety, future problems, or other ordinary areas of life. The issue is not that any one of these topics is inherently pathological. People can have serious, realistic reasons to worry about money, health, employment, war, migration, caregiving, or family safety.
Clinical judgment therefore depends on proportionality, persistence, intensity, generalization, and impact. A clinician considers whether the worry is excessive in its context, whether it spreads across domains, whether it persists beyond an adaptive problem-solving response, and whether it is associated with the broader GAD pattern. Context is essential because realistic danger and uncertainty can produce intense worry without automatically constituting a disorder.
Requirement 2: additional characteristic symptoms
The core apprehension or worry must be accompanied by additional characteristic symptoms. The ICD-11 description includes muscle tension or motor restlessness; sympathetic autonomic overactivity, which can include gastrointestinal symptoms, palpitations, sweating, trembling, shaking, or dry mouth; a subjective sense of nervousness, restlessness, or being on edge; difficulty concentrating; irritability; and sleep disturbance.
ICD-11 does not reduce GAD to bodily arousal. Nor does the presence of palpitations, gastrointestinal discomfort, tension, poor sleep, or concentration difficulty by itself identify GAD. These symptoms are nonspecific and can occur in many psychological and medical conditions. They become diagnostically meaningful only in relation to the full pattern.
ICD-11 does not require a fixed symptom count for GAD
A common search mistake is to look for an ICD-11 version of a numbered DSM-style checklist and ask how many symptoms are required. The ICD-11 GAD requirements do not specify a fixed minimum count of associated symptoms in the way DSM-5-TR specifies a numerical threshold from its associated-symptom list. The CDDR uses a clinically recognizable pattern of core and additional characteristic features.
This difference does not make ICD-11 diagnosis arbitrary. The required features, duration, functional threshold, and exclusions still constrain the diagnosis. It means that a clinician does not establish ICD-11 GAD simply by counting a fixed number of boxes. The comparison of ICD-11 and DSM-5 diagnostic requirements by First and colleagues discusses this broader difference in diagnostic organization and the specific differences for GAD.
Requirement 3: symptoms persist for at least several months, more days than not
ICD-11 requires the anxiety pattern to be non-transient. Symptoms persist for at least several months and occur for more days than not. The phrase “several months” is the diagnostic wording. It should not be silently converted into the DSM-5-TR six-month threshold.
This distinction is one of the clearest differences between the two systems. First et al. (2021) report that DSM-5 requires at least six months, whereas ICD-11 uses at least several months. The ICD-11 decision reflected evidence that GAD-like presentations shorter than six months can resemble longer-duration cases in onset, persistence, impairment, comorbidity, parental GAD, and sociodemographic correlates.
“More days than not” also matters. A difficult week, a few episodes of intense worry, or anxiety confined to a short-lived stressor does not by itself satisfy the temporal pattern. Duration must be interpreted together with the other requirements rather than used as a stand-alone diagnostic rule.
Requirement 4: the symptoms are not better accounted for by another mental disorder
ICD-11 requires clinicians to determine whether another mental disorder better explains the presentation. This is a differential-diagnosis requirement, not a rule that GAD can never co-occur with another disorder. ICD-11 removed several older hierarchical exclusion rules and allows clinically meaningful comorbidity when each disorder's own diagnostic requirements are met.
The distinction is especially important with depressive disorders. GAD and depression can share sleep problems, concentration difficulty, physical tension, distress, and pessimistic anticipation. The GAD diagnosis depends on the generalized apprehension or multi-domain worry pattern having its own clinical presence rather than being merely an expression of a depressive episode. The ICD-11 revisions and the removal of older hierarchical exclusions are discussed in the WHO-linked classification literature.
GAD and panic disorder
Panic disorder is organized around recurrent unexpected panic attacks and their consequences. GAD is organized around persistent generalized apprehension or worry. A person with GAD can have panic attacks. If attacks occur only in the context of the person's GAD worries or generalized apprehensiveness, ICD-11 allows a “with panic attacks” qualifier rather than automatically adding panic disorder. If recurrent unexpected panic attacks occur and the full requirements for panic disorder are met, both diagnoses may be appropriate.
That distinction was examined during ICD-11 development. In a global case-controlled field study involving 1,840 mental health professionals, the ICD-11 anxiety guidelines showed diagnostic accuracy and clinical utility that were equivalent or superior to ICD-10 overall, with significantly greater accuracy for GAD in the tested vignettes; the study also identified panic-attack boundaries as an area requiring careful application. See Rebello et al. (2020).
GAD and social anxiety, phobias, and agoraphobia
The focus of fear helps separate these conditions. Social anxiety disorder centers on feared negative evaluation in social situations. Specific phobia centers on a specific object or situation. Agoraphobia centers on multiple situations in which escape may be difficult or help unavailable if incapacitating or embarrassing symptoms occur. GAD can include worries about social, health, travel, or safety issues, but the overall pattern is generalized across everyday life rather than confined to the defining focus of one of these disorders.
GAD and OCD, PTSD, and health-focused conditions
Obsessive-compulsive disorder and post-traumatic stress disorder are not subtypes of anxiety disorder in ICD-11, even though anxiety can be prominent in both. OCD is organized around obsessions, compulsions, or related phenomena; PTSD requires a trauma-linked symptom pattern. Health-related anxiety can also arise in other diagnostic contexts. The presence of anxiety therefore does not collapse these conditions into GAD.
A clinician asks what the thoughts are about, how they are experienced, what triggers them, what behaviors follow, and which diagnostic pattern best accounts for the presentation. This is part of the broader process described in How Is Anxiety Diagnosed? Assessment, History, and Differential Diagnosis.
Requirement 5: medical conditions, substances, and medications must be considered
The ICD-11 GAD requirements state that the symptoms should not be a manifestation of another medical condition and should not be due to the effects of a substance or medication on the central nervous system, including relevant withdrawal effects. The CDDR gives examples such as hyperthyroidism and effects involving caffeine, cocaine, alcohol withdrawal, or benzodiazepine withdrawal.
This requirement matters because many physical sensations associated with anxiety are medically nonspecific. Palpitations, tremor, sweating, dizziness, gastrointestinal symptoms, sleep disruption, or concentration changes can have many causes. A mental-health article cannot determine the cause of a new or concerning physical symptom from symptom overlap alone. Clinical assessment may include medical history, medication and substance review, physical examination, or other evaluation when indicated.
Chest pain, fainting, severe shortness of breath, new neurological symptoms, sustained or irregular palpitations, or other potentially significant physical changes should not be presumed to be anxiety solely because anxiety is also present. The diagnostic task is to evaluate plausible medical and psychiatric explanations rather than using GAD as a default label.
Requirement 6: significant distress, impairment, or major additional effort
ICD-11 requires clinically meaningful impact. The symptoms must cause significant distress or significant impairment in personal, family, social, educational, occupational, or another important area of functioning. The CDDR also recognizes that some people maintain outward functioning only through substantial additional effort.
This point is easy to miss in self-assessment. A person may still go to work, study, care for children, or maintain relationships while spending extraordinary time and effort managing worry, seeking reassurance, preparing for unlikely outcomes, procrastinating, avoiding uncertainty, or recovering from chronic tension and poor sleep. Preserved performance does not automatically mean the clinical threshold is absent; the cost of maintaining that performance matters.
Normal worry versus ICD-11 GAD
Worry is a normal cognitive response to uncertainty, responsibility, and possible threat. It can direct attention, motivate planning, and support problem solving. The diagnostic boundary is not crossed simply because worry feels unpleasant. ICD-11 distinguishes GAD from normality through the combined pattern of excessiveness, persistence, intensity, generalized scope, characteristic symptoms, and significant distress or impairment.
The WHO anxiety disorders fact sheet likewise describes anxiety disorders as involving excessive fear or worry over an extended period, while noting that anxiety disorders include distinct conditions rather than one single disorder. For GAD specifically, the broad range of everyday worries is central.
Real-world context can shift the interpretation. If someone faces an immediate threat to safety, severe financial instability, a medical crisis, forced displacement, or another objectively dangerous situation, intense worry may be proportionate to circumstances. A clinician does not decide that a worry is “excessive” by ignoring the person's environment. The question is how the anxiety pattern relates to the actual context and whether the full diagnostic requirements are met.
Avoidance, reassurance seeking, and procrastination can occur, but they are not a separate required checklist
The ICD-11 CDDR notes behavioral changes that can accompany GAD, including avoidance, frequent reassurance seeking, and procrastination. These behaviors can function as attempts to reduce apprehension or prevent feared outcomes. They may help a clinician understand how anxiety is maintained or how much effort the person is spending to manage it.
Their presence is not equivalent to a diagnosis, and their absence does not automatically rule GAD out. They are additional clinical features rather than a substitute for the required anxiety pattern, duration, impact, and exclusions.
Culture and communication can change how GAD is expressed
ICD-11 was designed for global clinical use. The CDDR emphasizes that some people describe distress primarily through bodily symptoms, culturally shaped idioms, or a general sense of dread rather than through a detailed vocabulary of worry. Worry content also varies with social realities and cultural priorities.
This is one reason ICD-11 retains general apprehensiveness as an alternative core presentation. The point is not to treat every bodily complaint as anxiety. It is to avoid requiring one culturally narrow verbal style before a clinician can recognize the broader syndrome. The medical differential remains necessary when somatic symptoms are prominent.
Can GAD be diagnosed together with depression or another anxiety disorder?
Yes, ICD-11 can permit co-occurring diagnoses when the diagnostic requirements for each condition are independently satisfied and one disorder does not better account for the other. This is a change from older ICD approaches that used more hierarchical exclusions. The aim is to represent clinically relevant patterns that may each require attention.
Comorbidity should not be inferred from overlapping symptom lists. Sleep disturbance, concentration difficulty, irritability, autonomic arousal, or avoidance can appear in many conditions. Separate diagnoses require separate diagnostic justification.
ICD-11 GAD versus DSM-5-TR GAD
ICD-11 and DSM-5-TR describe closely related clinical territory, but their diagnostic requirements are not identical. A person should not assume that meeting one system's wording automatically means every requirement of the other system has been met.
Duration is the most visible difference: DSM-5-TR uses a six-month minimum, while ICD-11 requires at least several months. ICD-11 also allows generalized, free-floating apprehensiveness as an alternative to explicit excessive worry across multiple areas. The two systems use overlapping but not identical associated-symptom formulations. The comparative review by First et al. (2021) notes that ICD-11 includes sympathetic autonomic overactivity in its associated symptom description, whereas the DSM list includes easy fatigability.
ICD-11 also does not specify the same fixed count of associated symptoms used by DSM-5-TR. The two systems should therefore be read on their own terms. A dedicated English Hub page for the DSM-5-TR GAD criteria is reserved as a separate canonical article and will be linked here after it is live.
Does ICD-11 require that worry be difficult to control?
Difficulty controlling worry is a familiar DSM formulation, but the ICD-11 GAD diagnostic description is organized differently. ICD-11 emphasizes marked generalized apprehensiveness or excessive worry, accompanying characteristic symptoms, persistence, impairment or distress, and the relevant exclusions. It should not be rewritten into a DSM checklist by importing every DSM phrase as if it were an ICD-11 requirement.
In practice, inability to disengage from worry can still be clinically important when understanding severity and impairment. The key editorial and diagnostic point is to preserve the wording and structure of the classification system being explained.
GAD-7, the International Anxiety Questionnaire, and diagnosis
The GAD-7 is widely used to measure anxiety symptoms and support screening, but a GAD-7 score is not an ICD-11 diagnosis. Screening asks whether further assessment may be useful; diagnosis asks whether a specific clinical disorder's full requirements are met after evaluating context, duration, impairment, differential diagnoses, and other relevant information.
Researchers have developed the International Anxiety Questionnaire (IAQ) to align more closely with the ICD-11 GAD description. In its initial validation study, Shevlin and colleagues (2023) described the IAQ as directly derived from ICD-11 features and emphasized the need for further validation, including agreement with clinical interview assessment and research in clinical settings. Even a questionnaire designed around ICD-11 remains an assessment tool rather than a substitute for a formal clinical diagnosis.
How clinicians apply the ICD-11 GAD requirements
A competent diagnostic assessment usually builds a timeline rather than beginning with a score. The clinician clarifies when the anxiety began, whether it has been present for at least several months, how often it occurs, whether the apprehension is generalized or the worry spans several life domains, and which cognitive, emotional, physical, and behavioral features accompany it.
The assessment also examines functioning and distress, what the person does to manage uncertainty, whether panic attacks occur, whether mood episodes or other mental disorders better explain the pattern, and whether substances, medications, sleep problems, endocrine conditions, cardiovascular problems, or other medical issues require consideration. Which medical investigations are appropriate depends on the individual presentation.
Development of the ICD-11 guidelines included large international field testing. Rebello et al. (2020) found that clinicians using the ICD-11 anxiety guidelines were significantly more accurate in identifying GAD in the standardized cases than clinicians using ICD-10 guidelines, while also rating the new guidelines highly for clinical utility. That supports the classification's clinical usability; it does not turn a vignette study into proof that self-diagnosis from a webpage is reliable.
What this diagnosis does not mean
A GAD diagnosis does not mean every worry is irrational, that all physical symptoms are psychological, or that anxiety defines the person's personality. It identifies a clinically significant pattern according to a diagnostic classification. The diagnosis also does not explain a person's complete history, the causes of their symptoms, or which treatment will be best for them.
Likewise, having some GAD-like symptoms does not mean a person has GAD. Anxiety can be normal, situational, secondary to another mental disorder, related to a medical condition or substance, or part of another anxiety or fear-related disorder. For the larger diagnostic framework, see Anxiety Disorders: Symptoms, Types, Diagnosis, and Treatment.
When physical symptoms need separate medical attention
Because ICD-11 requires medical and substance explanations to be considered, it is important not to use an anxiety label to close a medical question prematurely. New chest pain, fainting, severe or unusual shortness of breath, new focal neurological symptoms, severe confusion, sustained irregular heartbeat, or a rapidly changing physical condition cannot be safely classified online as “just anxiety.”
The relevant action depends on severity, onset, associated symptoms, medical history, and local health-care access. The diagnostic principle is simple: symptom overlap is not proof of cause. Anxiety and a medical condition can also coexist.
Frequently asked questions about ICD-11 GAD requirements
What is the ICD-11 code for generalized anxiety disorder?
The ICD-11 code is 6B00. It is classified under anxiety or fear-related disorders.
How long must GAD symptoms last in ICD-11?
The ICD-11 wording is at least several months, with symptoms present for more days than not. It does not use the DSM-5-TR six-month minimum.
Does ICD-11 require a certain number of GAD symptoms?
ICD-11 does not specify a fixed minimum count of associated symptoms for GAD. It requires the core generalized apprehension or excessive multi-domain worry pattern together with characteristic additional symptoms, duration, impairment or distress, and diagnostic exclusions.
Can someone have ICD-11 GAD without naming specific worries?
Potentially, yes. ICD-11 allows general apprehensiveness that is not restricted to a particular environmental circumstance as one form of the essential anxiety presentation. A clinician still evaluates the rest of the diagnostic requirements.
Can panic attacks occur with GAD?
Yes. Panic attacks can occur in GAD. If they are limited to the GAD context, ICD-11 allows a “with panic attacks” qualifier. Recurrent unexpected panic attacks that meet the full requirements for panic disorder can justify a separate co-occurring diagnosis.
Is a high GAD-7 score enough for an ICD-11 GAD diagnosis?
No. GAD-7 is a symptom measure and screening tool. Diagnosis requires clinical assessment of the full disorder pattern, duration, functional impact, exclusions, and differential diagnoses.
Can GAD and depression both be diagnosed in ICD-11?
They can co-occur when each disorder's requirements are independently met and the GAD pattern is not better explained only by the depressive episode. Shared symptoms do not by themselves establish two diagnoses.
Is “anxiety attack” an ICD-11 diagnosis?
“Anxiety attack” is an informal expression rather than a specific ICD-11 diagnosis. Panic attacks have a defined clinical meaning, while generalized anxiety, panic disorder, and other anxiety or fear-related disorders have separate diagnostic requirements.
Can I diagnose myself with GAD from the ICD-11 requirements?
The requirements can help someone understand what clinicians assess, but self-matching cannot establish a formal diagnosis. The difficult parts of diagnosis are often the contextual ones: proportionality, impairment, medical causes, substance effects, competing disorders, comorbidity, and the longitudinal pattern.
Bottom line
ICD-11 GAD is a specific clinical pattern, not a synonym for feeling anxious or worrying a lot. The essential picture is marked generalized anxiety expressed as free-floating apprehensiveness or excessive worry across several everyday domains, accompanied by characteristic symptoms and present for more days than not for at least several months. The symptoms must cause significant distress or impairment, or require substantial extra effort to maintain functioning, and they must not be better explained by another mental disorder, a medical condition, or substance or medication effects.
The framework is intentionally clinical rather than score-based. Understanding it accurately means preserving the difference between a symptom and a disorder, between screening and diagnosis, and between ICD-11 and DSM-5-TR rather than blending the systems into one checklist.
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References
First, M. B., Gaebel, W., Maj, M., Stein, D. J., Kogan, C. S., Saunders, J. B., et al. (2021). An organization- and category-level comparison of diagnostic requirements for mental disorders in ICD-11 and DSM-5. World Psychiatry, 20(1), 34–51. https://doi.org/10.1002/wps.20825
Kogan, C. S., Stein, D. J., Maj, M., First, M. B., Emmelkamp, P. M. G., & Reed, G. M. (2016). The classification of anxiety and fear-related disorders in the ICD-11. Depression and Anxiety, 33(12), 1141–1154. https://doi.org/10.1002/da.22530
Rebello, T. J., Keeley, J. W., Kogan, C. S., Sharan, P., Matsumoto, C., Kuligyna, M., et al. (2020). Anxiety and fear-related disorders in the ICD-11: Results from a global case-controlled field study. Archives of Medical Research, 50(8), 490–501. https://doi.org/10.1016/j.arcmed.2019.12.012
Shevlin, M., Hyland, P., Butter, S., McBride, O., Hartman, T. K., Karatzias, T., & Bentall, R. P. (2023). The development and initial validation of self-report measures of ICD-11 depressive episode and generalized anxiety disorder: The International Depression Questionnaire (IDQ) and the International Anxiety Questionnaire (IAQ). Journal of Clinical Psychology, 79, 854–870. https://doi.org/10.1002/jclp.23446
World Health Organization. (2024). Clinical descriptions and diagnostic requirements for ICD-11 mental, behavioural and neurodevelopmental disorders (CDDR). https://www.who.int/publications/i/item/9789240077263
World Health Organization. (2026). Anxiety disorders. https://www.who.int/news-room/fact-sheets/detail/anxiety-disorders