WHO ICD-11 Research Articles

Barriers and facilitators to the implementation of guidelines in rare diseases: a systematic review

BackgroundRare diseases present a challenge to guideline implementation due to a low prevalence in the general population and the unfamiliarity of healthcare professionals. Existing literature in more common diseases references barriers and facilitators to guideline implementation. This systematic review aims to identify these barriers and facilitators in rare diseases from existing literature.MethodsA multi-stage strategy included searching MEDLINE PubMed, EMBASE Ovid, Web of Science and Cochrane library from the earliest date available to April 2021, Orphanet journal hand-search, a pearl-growing strategy from a primary source and reference/citation search was performed. The Integrated Checklist of Determinants of Practice which comprises of twelve checklists and taxonomies, informed by 57 potential determinants was selected as a screening tool to identify determinants that warrant further in-depth investigation to inform design of future implementation strategies.ResultsForty-four studies were included, most of which were conducted in the United States (54.5%). There were 168 barriers across 36 determinants (37 studies) and 52 facilitators across 22 determinants (22 studies). Fifteen diseases were included across eight WHO ICD-11 disease categories. Together individual health professional factors and guideline factors formed the majority of the reported determinants (59.5% of barriers and 53.8% of facilitators). Overall, the three most reported individual barriers were the awareness/familiarity with the recommendation, domain knowledge and feasibility. The three most reported individual facilitators were awareness/familiarity with the recommendation, agreement with the recommendation and ability to readily access the guidelines. Resource barriers to implementation included technology costs, ancillary staff costs and more cost-effective alternatives. There was a paucity of studies reporting influential people, patient advocacy groups or opinion leaders, or organisational factors influencing implementation.ConclusionsKey barriers and facilitators to the implementation of clinical practice guidelines in the setting of rare diseases were at the individual health professional and guideline level. Influential people and organisational factors were relatively under-reported and warrant exploration, as does increasing the ability to access the guidelines as a potential intervention.

Optimization of the allergen classification of the International Classification Of Diseases, 11th Revision (ICD-11)

Accurate diagnosis of triggers or causative allergens is essential for appropriate risk assessment, providing correct advice to patients with allergy and their caregivers and personalized treatment. However, allergens have never been represented in the World Health Organization International Classification of Diseases (ICD). In this article, we present the process of selection of allergens to better fit the ICD, 11th Revision (ICD-11) structure and the outcomes of this process. The Logical Observation Identifiers Names and Codes database, containing 1444 allergens, was used as the basis for the selection process. Two independent experts were responsible for the first selection of the allergens according to specific technical criteria. The second step of the selection process was based on real-life relevance of the allergens according to the frequency of requests regarding each of them. We selected 1109 allergens (76.8%) from all 1444 present in the Logical Observation Identifiers Names and Codes database, with considerable agreement between experts (Cohen κ= 8.6). After assessment of real-life data, 297 additional relevant allergens worldwide were selected and grouped as plants (36.4%), drugs (32.6%), animal proteins (21%), mold and other microorganisms (1.5%), occupational allergens (0.4%), and miscellaneous allergens (0.5%). The stepwise approach allowed us to select the most relevant allergens in practice, which is the first step to building a classification of allergens for the WHO ICD-11. Aligned with the achievement in the construction of the pioneer section addressed to the allergic and hypersensitivity conditions in the ICD-11, the introduction of a classification for allergens can be considered timely and much needed in clinical practice.

Examination of ICD-11 PTSD and CPTSD using the International Trauma Questionnaire – Child and Adolescent version (ITQ-CA) in a sample of Danish children and adolescents exposed to abuse

ABSTRACT Background: International research has established that children and adolescents are at risk for posttraumatic stress disorder (PTSD) and complex PTSD (CPTSD) as defined by the WHO ICD-11. There is a need for a Danish language version of the International Trauma Questionnaire – Child and Adolescent (ITQ-CA) to assess symptoms of PTSD and CPTSD. Objective: To test the ICD-11 formulations of PTSD and DSO (Disturbances of Self-Organization) using the ITQ-CA version in a sample of children exposed to abuse. Additionally, to study the distribution of symptoms and probable prevalence of ICD-11 PTSD and CPTSD among the population of children exposed to violence or sexual abuse. Method: Confirmatory factor analysis of competing models of the dimensionality of the ITQ-CA was tested among a sample of 119 children and adolescents that were referred to the Danish Children Centres on suspicion of physical or sexual abuse or both. Latent class analysis (LCA) was used to study the distribution of symptoms and consequences of different operationalisations of functional impairment were explored. Results: Findings supported a two-factor second-order model corresponding to the operationalisation of CPTSD in ICD-11 as the best representation of the data. Findings from the LCA suggested that symptoms were distributed in a pattern consistent with the ICD-11 proposal for CPTSD. CPTSD was more prevalent than PTSD regardless of the operationalisation of functional impairment. Conclusion: ITQ-CA is a valid tool for identifying symptoms of ICD-11 PTSD and CPTSD among Danish children exposed to physical or sexual abuse. Further research is needed to study the relationship between ICD-11 C/PTSD symptomatology and anxiety and depression in this population.

Validation of the Digital Eye Strain Questionnaire and pilot application to online gaming addicts.

'Digital eye strain' (DES) is a clinical syndrome with eyesight symptoms related to continuous engagement in front of a screen-enabled digital device. With use of these devices constantly on the rise, the related symptoms have become prominent, even in younger ages. This study describes the process of validating the Digital Eye Strain Questionnaire (DESQ), a thirteen-item self-report scale in a yes-no format designed to offer a measure of complaints related to digital eye strain syndrome (DES). The validation process included 150 outpatients with no long-standing eye disease who were examined for various eye complaints and 50 outpatients who were diagnosed with gaming addiction according to WHO ICD-11 clinical criteria. All participants filled in a demographics questionnaire, the DESQ, the Computer Vision Syndrome Questionnaire (CVS-Q) and the Problematic Internet Use Questionnaire-9 (PIUQ-9). Principal component analysis of categorical variables confirmed the proposed three-factor DES structure with a total of 61.02% of explained variance and Cronbach's alpha equal to.94. Concurrent validity was assessed by comparing the results of the DESQ to the CVS-Q while convergent validity was assessed by examining correlations of the DESQ with results from the PIUQ-9 questionnaire. In all cases the DESQ demonstrated excellent reliability and validity. Results indicate that the DESQ questionnaire can be employed to reliably measure the symptomatology of digital eye strain in clinical populations who present either with eye issues or with excessive use of the gaming and screen-enabled devices in general.

Preliminary study of patient safety and quality use cases for ICD-11 MMS.

This study investigated how well-suited the International Classification of Diseases, 11th Revision, for Mortality and Morbidity Statistics, (ICD-11 MMS) is for 2 morbidity use cases, patient safety and quality, examining the level of detail captured, and evaluating the necessity for the development of a US clinical modification (CM). Utilizing the 5 NCVHS-specified perspectives plus the consumer perspective, a framework was created of International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10-CM) use cases. Analysis yielded candidate source criteria for use in case evaluation. Patient safety and quality were chosen because they are relevant across all perspectives.Granularity differences and content coverage of ICD-11 MMS entities were assessed pre- and post-coordination to determine suitability for the 2 use cases. Pressure ulcers, a common condition across 3 patient safety applications, became the focus for comparing ICD-10-CM codes to ICD-11 MMS codes. For 3 electronic clinical quality measures (eCQMs), the evaluation centered on specified value sets for ischemic stroke, hypertension, and diabetes. For pressure ulcers, the ICD-11 MMS was found to exceed ICD-10-CM capabilities via post-coordinated extension codes. For the 3 eCQM value sets explored, the ICD-11 MMS fully represented the disease concepts when post-coordinated code clusters were used. The examples from the patient safety and quality use cases evaluated in this study are appropriate for ICD-11 MMS. It captures greater detail than ICD-10-CM, and ICD-11 MMS specificity would benefit both use cases. The authors believe this preliminary study indicates the US should invest resources to explore adopting the WHO ICD-11 MMS and tooling and guidelines to implement post-coordination.

The ICD-11 Personality Disorder Trait Model Fits the Kurdish Population Better Than the DSM-5 Trait Model.

The ICD-11 Classification of Personality Disorders and the DSM-5 Alternative Model of Personality Disorders (AMPD) operate with trait domains that contribute to the individual expression of personality disturbance (i.e., negative affectivity, detachment, dissociality, disinhibition, anankastia, and psychoticism). To date, these trait frameworks have not been investigated sufficiently in Middle Eastern cultures. Thus, the present study explored the structure of the ICD-11 and AMPD personality disorder (PD) trait domains in a large mixed sample from the Kurdistan zone of Iran. The ICD-11 and AMPD trait domains were operationalized using empirically supported algorithms for the Personality Inventory for DSM-5 (PID-5). The PID-5 was administered to a large mixed sample (N = 3,196) composed of 2,678 community and 518 clinical participants. Structural validity was investigated using Exploratory Factor Analysis (EFA), whereas differential construct validity was explored by comparing clinical and community scores. Model fit and the expected factor structure were deemed appropriate for the ICD-11 trait model, but less adequate for the DSM-5 trait model (i.e., disinhibition did not emerge as a separate factor). All domain and facet scores showed significant differences between clinical and community subsamples with moderate to large effects, mostly for disinhibition and dissociality/antagonism while least for anankastia. The findings of the present study may suggest that the ICD-11 trait model is more cross-culturally fitting than the DSM-5 AMPD trait model, at least with respect to a large mixed sample from the region of Kurdistan. Accordingly, there is evidence for using PID-5 data for WHO ICD-11 purposes in this part of the World.

Tinnitus and tinnitus disorder: Theoretical and operational definitions (an international multidisciplinary proposal).

As for hypertension, chronic pain, epilepsy and other disorders with particular symptoms, a commonly accepted and unambiguous definition provides a common ground for researchers and clinicians to study and treat the problem. The WHO's ICD11 definition only mentions tinnitus as a nonspecific symptom of a hearing disorder, but not as a clinical entity in its own right, and the American Psychiatric Association's DSM-V doesn't mention tinnitus at all. Here we propose that the tinnitus without and with associated suffering should be differentiated by distinct terms: "Tinnitus" for the former and "Tinnitus Disorder" for the latter. The proposed definition then becomes "Tinnitus is the conscious awareness of a tonal or composite noise for which there is no identifiable corresponding external acoustic source, which becomes Tinnitus Disorder "when associated with emotional distress, cognitive dysfunction, and/or autonomic arousal, leading to behavioural changes and functional disability.". In other words "Tinnitus" describes the auditory or sensory component, whereas "Tinnitus Disorder" reflects the auditory component and the associated suffering. Whereas acute tinnitus may be a symptom secondary to a trauma or disease, chronic tinnitus may be considered a primary disorder in its own right. If adopted, this will advance the recognition of tinnitus disorder as a primary health condition in its own right. The capacity to measure the incidence, prevalence, and impact will help in identification of human, financial, and educational needs required to address acute tinnitus as a symptom but chronic tinnitus as a disorder.

Patient descriptions of loss of control and eating episode size interact to influence expert diagnosis of ICD-11 binge-eating disorder.

BackgroundAlthough data suggest that the sense of “loss of control” (LOC) is the most salient aspect of binge eating, the definition of LOC varies widely across eating disorder assessments. The WHO ICD-11 diagnostic guidelines for binge eating do not require an objectively large amount of food, which makes accurate LOC diagnosis even more critical. However, it can be especially challenging to assess LOC in the context of elevated weight status and in the absence of compensatory behaviors. This ICD-11 field sub-study examined how descriptions of subjective experience during distressing eating episodes, in combination with different eating episode sizes, influence diagnoses of binge-eating disorder (BED).MethodMental health professionals with eating disorder expertise from WHO’s Global Clinical Practice Network (N = 192) participated in English, Japanese, and Spanish. Participants were asked to select the correct diagnosis for two randomly assigned case vignettes and to rate the clinical importance and ease of use of each BED diagnostic guideline.ResultsThe presence of LOC interacted with episode size to predict whether a correct diagnostic conclusion was reached. If the amount consumed during a typical distressing eating episode was only subjectively large compared to objectively large, clinicians were 23.1 times more likely to miss BED than to correctly diagnose it, and they were 9.7 times more likely to incorrectly diagnose something else than to correctly diagnose BED. In addition, clinicians were 10.8 times more likely to make a false positive diagnosis of BED when no LOC was described if the episode was objectively large. Descriptions of LOC that were reliably associated with correct diagnoses across episodes sizes included two that are similar to those already included in proposed ICD-11 guidelines and a third that is not. This third description of LOC focuses on giving up attempts to control eating because perceived overeating feels inevitable.ConclusionsResults highlight the importance of detailed clarification of the LOC construct in future guidelines. Explicitly distinguishing LOC from distressing and mindless overeating could help promote consistent and accurate diagnosis of BED versus another or no eating disorder.

Development of the international prolonged grief disorder scale for the ICD-11: Measurement of core symptoms and culture items adapted for chinese and german-speaking samples

BackgroundProlonged grief disorder (PGD) is a new mental health disorder included in the WHO ICD-11 however, the operationalization of the guidelines still needs to be empirically validated, particularly in different cultural contexts. Here we provide a preliminary validation study of the new International Prolonged Grief Disorder Scale (IPGDS) that serves to be the first self-report questionnaire directly based on the ICD-11 PGD and contains culturally adapted items. MethodsIn addition to core symptom items new culturally specific items were developed in two phases. Phase 1: key informant interviews with 10 German-speaking and 14 Chinese experts in grief and mental health, followed by a focus group with four bereaved German-speaking participants. Phase 2: 214 German-speaking and 325 Chinese bereaved participants completed self-report questionnaires. ResultsPhase 1 resulted in 19 potential culturally relevant items (e.g. feeling stuck in grief). Phase 2 exploratory factor analysis confirmed the one-dimensional nature of the IPGDS, additionally the 32-item scale revealed two factors (core grief and culturally specific symptoms). Psychometric analysis revealed strong internal consistency, concurrent validity and criterion validity. LimitationsThe German-speaking and Chinese samples significantly differed in terms of several demographic variables including age, gender and type of loss. ConclusionsThis preliminary validity study confirms that the IPGDS is a valid and reliable measure of the new ICD-11 PGD guidelines. This is the first scale of disordered grief to contain both core items and culturally specific supplementary items and aims to improve the clinical utility of the ICD-11 narrative approach.

Traditional Medicine Chapter in WHO ICD-11

Traditional Medicine Chapter in WHO ICD-11

Recognition and correct classification of pressure ulcers: aposition paper

Pressure ulcers comprise serious skin and tissue damage. The correct diagnosis and classification into different categories is often difficult in daily practice. What procedure can be recommended to correctly diagnose and classify pressure ulcers in practice? The society Initiative Chronische Wunden (ICW) e. V. established agroup of experts who developed practical recommendations for the diagnosis and classification of pressure ulcers based on the current literature and their own expertise. Pressure ulcers should only be diagnosed if skin and/or tissue damage is most likely due to prolonged pressure or pressure associated with shear forces. Acomplete anamnesis must be performed to detect periods of previous prolonged immobility. Pressure ulcers are usually located at typical predilection sites. For categoryI and "suspected deep tissue damage" the tissue damage occurs under (initially) intact skin. However, the diagnosis is uncertain and the classification should be made later. The categoryII pressure ulcer is usually an exclusion diagnosis. The categoriesIII andIV are pressure ulcers in the proper sense. As long as the distinction between categoryIII andIV is not possible, the lower category should be coded. Currently, arelevant classification should be used uniformly for the respective setting. In accordance with the clinical picture, amost suitable diagnosis is to be made. It does not matter which classification system is used. The future WHO ICD-11 version will allow better classification of pressure ulcers.

What can we learn in drug allergy management from World Health Organization's international classifications?

Drug hypersensitivity reactions (DHRs) represent growing health problem worldwide, affecting more than 7% of the general population, and represent an important public health problem. However, knowledge in DHRs morbidity and mortality epidemiological data is still not optimal and international comparable standards remain poorly accessed. Institutional databases worldwide increasingly use the WHO International Classification of Diseases (ICD) system to classify diagnoses, health services utilization, and death data. The misclassification of disorders in the ICD system contributes to a lack of ascertainment and recognition of their importance for healthcare planning and resource allocation. It also hampers clinical practice and prevention actions. To further inform the allergy community and to ensure that the revision process is transparent as advised in the WHO ICD-11 revision agenda, we report the advances and use of the pioneering "Drug hypersensitivity" subsection of ICD-11 and implementation in the WHO International Classification of Health Interventions (ICHI). The new classification addressed to DHRs will enable the collection of more accurate epidemiological data to support quality management of patients with drug allergies and better facilitate healthcare planning and decision-making and public health measures to prevent and reduce the morbidity and mortality attributable to DHRs.

The True North Strong and Free? Opportunities for Improving Canadian Mental Health Care and Education by Adopting the WHO's ICD-11 Classification.

The True North Strong and Free? Opportunities for Improving Canadian Mental Health Care and Education by Adopting the WHO's ICD-11 Classification.

The WHO ICD-11 classification and diagnosis of mental disorder in people with disorders of intellectual development (PWDID): An international study on clinical utility

IntroductionConstituting 2% of the population, PWDID are a vulnerable group with a higher prevalence of mental disorders than the general population. ICD diagnostic criteria often rely on adequate cognitive functioning and hence diagnosis of mental disorders in PWDID can be difficult, consequently leading to inequity of treatment, prognosis and stigma. Our study critically analysed the available evidence base and explored the feasibility of applying modified diagnostic criteria within the context of cumulative iterative iteration. We present the outcome using diagnosis of DID and anxiety disorder as examples.AimsAddress current shortcomings in ICD classification regarding PWDID by contributing effectively to the WHO ICD-11 consultation process in collaboration with international stakeholders.ObjectivesFacilitate accessibility of ICD-11 criteria for diagnosis of mental disorders capable of engendering robust evidence based epidemiological data and healthcare in PWDID.MethodsWe evaluated current evidence via a systematic literature search utilising PRISMA guidelines and developed pragmatic guidelines to adapt ICD diagnostic criteria in PWDID. A brief screener [Glasgow Level of Ability and Development Scale (GLADs)] for detecting DID was also studied internationally within the context of clinical utility (n = 136).ResultsThe evidence base relating to mental disorders in PWDID is poor, significantly hampered by difficulties in applicability of diagnostic criteria. The GLADs appears to be a promising screening tool with good clinical utility for detecting disorders of intellectual development (DID) particularly where resources are scarce.ConclusionsPragmatic modifications to ICD-11 diagnostic criteria and the GLADS tool facilitates its clinical utility for PWDID and contributes significantly to enhancing research based evidence, and, ultimately their health access and well-being.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Adjustment disorder: Empirical study of a new diagnostic concept for ICD-11 in the general population in Lithuania

ObjectiveAdjustment disorder (AD) is one of the most debated diagnoses in psychiatry since it has been recognised as vaguely defined and causing a lot of difficulties in clinical practice. We aimed to analyse the structure of adjustment disorder based on International Classification of Diseases (ICD)–11 proposals by the WHO ICD-11 Working Group on the Classification of Disorders Specifically Associated with Stress in the general population in Lithuania. Three structural models of adjustment disorder were tested using Confirmatory Factor Analysis (CFA). MethodData from the sample of 649 participants who experienced at least one significant stressor during the last two years was included in CFA analysis. Stressor exposure and AD symptoms were measured with the Lithuanian version of the Adjustment Disorder New Module (ADNM-20). ResultsThe CFA analysis revealed that the two core factor model of the AD with two core symptoms: preoccupation and failure to adapt fitted data the best in contrast to other two models. ConclusionThe study supports the ICD-11 proposal for the structure of adjustment disorder with two core symptoms: preoccupation and failure to adapt. Further studies are needed to analyse the structure of AD in other populations.

Review and proposed improvements for Romanization and English expressions of rubrics in the WHO ICD－11 beta version traditional medicine chapter※

Review and proposed improvements for Romanization and English expressions of rubrics in the WHO ICD－11 beta version traditional medicine chapter^※

Capturing diagnosis-timing in ICD-coded hospital data: recommendations from the WHO ICD-11 topic advisory group on quality and safety.

To develop a consensus opinion regarding capturing diagnosis-timing in coded hospital data. As part of the World Health Organization International Classification of Diseases-11th Revision initiative, the Quality and Safety Topic Advisory Group is charged with enhancing the capture of quality and patient safety information in morbidity data sets. One such feature is a diagnosis-timing flag. The Group has undertaken a narrative literature review, scanned national experiences focusing on countries currently using timing flags, and held a series of meetings to derive formal recommendations regarding diagnosis-timing reporting. The completeness of diagnosis-timing reporting continues to improve with experience and use; studies indicate that it enhances risk-adjustment and may have a substantial impact on hospital performance estimates, especially for conditions/procedures that involve acutely ill patients. However, studies suggest that its reliability varies, is better for surgical than medical patients (kappa in hip fracture patients of 0.7-1.0 versus kappa in pneumonia of 0.2-0.6) and is dependent on coder training and setting. It may allow simpler and more precise specification of quality indicators. As the evidence indicates that a diagnosis-timing flag improves the ability of routinely collected, coded hospital data to support outcomes research and the development of quality and safety indicators, the Group recommends that a classification of 'arising after admission' (yes/no), with permitted designations of 'unknown or clinically undetermined', will facilitate coding while providing flexibility when there is uncertainty. Clear coding standards and guidelines with ongoing coder education will be necessary to ensure reliability of the diagnosis-timing flag.

Categories that should be removed from mental disorders classifications: perspectives and rationales of clinicians from eight countries.

To explore the rationales of mental health professionals (mainly psychiatrists and psychologists) from 8 countries for removing specific diagnostic categories from mental disorders classification systems. As part of a larger study, 505 participants indicated which of 60 major disorders should be omitted from mental disorders classification systems and provided rationales. Rationale statements were analyzed using inductive content analysis. The majority of clinicians (60.4%) indicated that 1 or more disorders should be removed. The most common rationales were (a) problematic boundaries between normal and psychopathological conditions (45.9% of total removal recommendations), (b) problematic boundaries among mental disorders (25.4%), and (c) problematic boundaries between mental and physical disorders (24.0%). The categories most frequently recommended for deletion were gender identity disorder, sexual dysfunction, and paraphilias, usually because clinicians viewed these categories as being based on stigmatization of a way of being and behaving. A range of neurocognitive disorders were described as better conceptualized as nonpsychiatric medical conditions. Results were analyzed by country and country income level. Although gender identity disorder was the category most frequently recommended for removal overall, clinicians from Spain, India, and Mexico were most likely to do so and clinicians from Nigeria and Japan least likely, probably because of social and systemic factors that vary by country. Systematic differences in removal rationales by country income level may be related to the development, structure, and functioning of health systems. Implications for development and dissemination of the classification of mental and behavioral disorders in WHO's ICD-11 are discussed.

Stereotyped movement disorder in ICD-11.

According to current proposals for ICD-11, stereotyped movement disorder will be classified in the grouping of neurodevelopmental disorders, with a qualifier to indicate whether self-injury is present, similar to the classification of stereotypic movement disorder in DSM-5. At the same time, the WHO ICD-11 Working Group on the Classification of Obsessive-Compulsive and Related Disorders has proposed a grouping of body-focused repetitive behavior disorders within the obsessive-compulsive and related disorders (OCRD) cluster to include trichotillomania and skin-picking disorder. DSM-5 has taken a slightly different approach: trichotillomania and excoriation (skin picking) disorder are included in the OCRD grouping, while body-focused repetitive behavior disorder is listed under other specified forms of OCRD. DSM-5 also includes a separate category of nonsuicidal self-injury in the section on "conditions for further study." There are a number of unresolved nosological questions regarding the relationships among stereotyped movement disorder, body-focused repetitive behavior disorders, and nonsuicidal self-injury. In this article, we attempt to provide preliminary answers to some of these questions as they relate to the ICD-11 classification of mental and behavioral disorders.

Tourette and tic disorders in ICD-11: standing at the diagnostic crossroads.

This article reflects discussion by the WHO ICD-11 Working Group on the Classification of Obsessive-Compulsive and Related Disorders. After reviewing the historical classification of tic disorders, this article discusses their placement in ICD-11. Existing problems with diagnostic labels and criteria, appropriate placement of the tic disorders category within the ICD-11 system, and pragmatic factors affecting classification are reviewed. The article ends with recommendations to (a) maintain consistency with the DSM-5 diagnostic labels for tic disorders, (b) add a minimum duration guideline for a provisional tic disorder diagnosis, (c) remove the multiple motor tic guideline for the diagnosis of Tourette disorder, and (d) co-parent the tic disorder diagnoses in the disorders of the nervous system and the mental and behavioral disorders categories, with secondary co-parenting in the obsessive-compulsive and related disorders and neurodevelopmental disorders sections.