What to do about atypical anorexia nervosa? Commentary on Walsh et al. (2023).

Changes made to the DSM Eating Disorders over the years have aimed to reduce the prevalence of the residual DSM Eating Disorder categories (e.g., Other Specified Eating Disorder). Atypical Anorexia Nervosa (AN), included since DSM-IV as an example of a presentation not meeting criteria for a specific eating disorder, appears to be more prevalent than AN. It is defined as meeting all of the criteria for AN except that, after significant weight loss, weight is at or above normal. As suggested by the Walsh et al. review, lack of definitional precision will likely complicate efforts to determine whether atypical AN is best considered a variant of AN or a distinct category. Problems with the current definition of atypical AN include (1) a lack of precision regarding what constitutes "significant" weight loss; (2) whether the weight loss can occur at any point in the individual's lifetime; and (3) whether there an upper limit to weight being above normal. It is suggested that researchers develop consensus diagnostic criteria and assessment tools to facilitate the collection of empirical data about atypical AN in order to lay the groundwork for future decisions about its nosological status.

Diagnostic criteria in dementing illness. What's new? / Criterios diagnósticos en la enfermedad demencial ¿Qué hay de nuevo?

The spectrum of neurodegenerative diseases that primarily affect cognition and behaviorspreads from asymptomatic preclinical disease to very mild cognitive impairment to frank dementia. Alzheimer's disease (AD) is the most common cause of a decline in cognitive ability. Also, it is a devastating condition that affects patients and their entirefamilies of caregivers, exacting tremendous financial hardships. Diagnosis may be complicated by other forms of dementia that have symptoms and pathologies similar to AD. Knowing the key features and pathology of each type of dementia can help in the accurate diagnosis of patients, so they will receive the treatment and support services appropriate for their condition and maintain the highest possible functioning in daily life and quality of life. Differentiate, based on clinical criteria, neuropathology, and biomarkers, AD and its atypical variants from other common dementias including Dementia with Lewy Bodies, Vascular Cognitive Impairment, Frontotemporal Degeneration, and less frequent cognitive disorders. The importance of getting an accurate and early diagnosis of dementiais now increasingly significant to make important decisions about treatment, support, and care. Nonpharmacological as well as pharmacological interventions should be initiated once the diagnosis is obtained. Biochemical markers to identify Alzheimer's disease play a central role in the new diagnostic criteria for the disease and in the recent biological definition of AD. This review article presents up-to-date data regarding the recent diagnostic criteria of Alzheimer´s disease and related disorders, emphasizing its usefulness in routine clinical practice.

El espectro de enfermedades neurodegenerativas que afectan principalmente a la cognición y el comportamiento abarca desde la enfermedad preclínica asintomática hasta el deterioro cognitivo muy leve y la demencia franca. La enfermedad de Alzheimer (EA) es la causa más común de deterioro de la capacidad cognitiva. Es una enfermedad devastadora que afecta a los pacientes y a toda su familia de cuidadores, lo que supone enormes dificultades socioeconómicas y psicoemocionales. El diagnóstico puede complicarse debido a otras formas de demencia que presentan síntomas y patologías similares a la EA. Los marcadores bioquímicos para identificar la enfermedad de Alzheimer desempeñan un papel central en los nuevos criterios diagnósticos de la enfermedad y en la reciente definición biológica de la EA. Conocer las características claves y la patología de cada tipo de demencia puede ayudar en el diagnóstico preciso de los pacientes, a fin de que reciban el tratamiento y los servicios de apoyo adecuados a su condición y mantengan el mayor funcionamiento posible en la vida diaria y la calidad de vida. Por lo tanto es prioritario diferenciar, basándose en criterios clínicos, neuropatología y biomarcadores, la EA y sus variantes atípicas de otras demencias comunes como el Deterioro Cognitivo Vascular, la Degeneración Fronto- temporal entre otras, y los trastornos cognitivos menos frecuentes. Este artículo de revisión presenta datos actualizados relativos a los recientes criterios diagnósticos de algunas formas de demencia haciendo hincapié en su utilidad en la práctica clínica habitual. Se exponen los criterios de EA, de Demencia Vascular (DV), de la demencia Fronto-temporal (DFT) y de una forma rara de demencia, descripta en los últimos años, que se evidencia en pacientes muy añosos con un perfil similar a la EA. Se trata de la encefalopatía predominantemente límbica por tdp- 43 relacionada a la edad (LATE).

Biomarkers for the Diagnosis of Alzheimer's Disease in Clinical Practice: The Role of CSF Biomarkers during the Evolution of Diagnostic Criteria.

Alzheimer's disease (AD) is a progressive condition and the most common cause of dementia worldwide. The neuropathological changes characteristic of the disorder can be successfully detected before the development of full-blown AD. Early diagnosis of the disease constitutes a formidable challenge for clinicians. CSF biomarkers are the in vivo evidence of neuropathological changes developing in the brain of dementia patients. Therefore, measurement of their concentrations allows for improved accuracy of clinical diagnosis. Moreover, AD biomarkers may provide an indication of disease stage. Importantly, the CSF biomarkers of AD play a pivotal role in the new diagnostic criteria for the disease, and in the recent biological definition of AD by the National Institute on Aging, NIH and Alzheimer's Association. Due to the necessity of collecting CSF by lumbar puncture, the procedure seems to be an important issue not only from a medical, but also a legal, viewpoint. Furthermore, recent technological advances may contribute to the automation of AD biomarkers measurement and may result in the establishment of unified cut-off values and reference limits. Moreover, a group of international experts in the field of AD biomarkers have developed a consensus and guidelines on the interpretation of CSF biomarkers in the context of AD diagnosis. Thus, technological advancement and expert recommendations may contribute to a more widespread use of these diagnostic tests in clinical practice to support a diagnosis of mild cognitive impairment (MCI) or dementia due to AD. This review article presents up-to-date data regarding the usefulness of CSF biomarkers in routine clinical practice and in biomarkers research.

Qualitative Research in Veterinary Medical Education: Part 1-Principles of Qualitative Design.

Qualitative methodologies are relative newcomers to health sciences education research. While they may look very different to their quantitative counterparts in terms of size and scope, when well-applied they offer a fresh perspective and generate valuable research findings. Although qualitative research is being increasingly conducted in veterinary medical education, there are few contextualized resources to assist those who would like to develop their expertise in this area. In this article, we address this by introducing the principles of qualitative research design in a veterinary medical education context. Drawing from a range of contemporary resources, we explore the types of research goals and questions that are amenable to qualitative inquiry and discuss the process of formulating a worthwhile research question. We explain what research paradigms are and introduce readers to some of the methodological options available to them in qualitative research. Examples from veterinary medical education are used to illustrate key points. In a second companion article, we will focus on the decisions that need to be made regarding data sampling, collection, and analysis. We will also consider how qualitative research is evaluated, and discuss how qualitative findings are applied. Taken together, the two articles build an understanding of qualitative research, illuminate its potential to contribute to the scholarship of teaching and learning in veterinary medical education, and equip readers with an improved capacity to appraise its value.

Qualitative Research in Veterinary Medical Education: Part 2-Carrying Out Research Projects.

This is the second of two articles that together comprise an orientation and introduction to qualitative research for veterinary medical educators who may be new to research, or for those whose research experience is based on the quantitative traditions of biomedicine. In the first article (Part 1-Principles of Qualitative Design), we explored the types of research interests and goals suited to qualitative inquiry and introduced the concepts of research paradigms and methodologies. In this second article, we move to the strategies and actions involved in conducting a qualitative study, including selection and sampling of research sites and participants, data collection and analysis. We introduce some guidelines for reporting qualitative research and explore the ways in which qualitative research is evaluated and the findings applied. Throughout, we provide illustrative examples from veterinary and human medical education and suggest useful resources for further reading. Taken together, the two articles build an understanding of qualitative research, outline how it may be conducted, and equip readers with an improved capacity to appraise its value.

A Prospective Validation of the Updated Movement Disorders Society Research Criteria for Prodromal Parkinson's Disease.

OBJECTIVE: The objective of this study was to validate the recently updated research criteria for prodromal Parkinson's disease (pPD) proposed by the International Parkinson's Disease and Movement Disorders Society. METHODS: A total of 16 of 21 markers of pPD were ascertained in the Hellenic Longitudinal Investigation of Aging and Diet cohort composed of community-dwelling individuals aged ≥65 years. The probability of pPD was calculated for 961 individuals without Parkinson's disease (PD) or dementia with Lewy bodies at baseline who were followed-up for a median of 3 years. The ability of the criteria to predict conversion to PD/dementia with Lewy bodies was assessed by estimating their sensitivity and specificity, plotting receiver operating characteristics curves, and using logistic regression. These analyses were repeated using the original criteria. RESULTS: No incident PD/dementia with Lewy bodies case had probable pPD at baseline (ie, ≥80% pPD probability). At cut-offs of 10%, 30%, and 50% probability of pPD, the sensitivity and specificity of the criteria ranged from 4.5% to 27.3%, and 85.7% to 98.3% respectively. The area under the receiver operating characteristics curve was 0.691 (95% confidence intervals, 0.605-0.777). In logistic regression models, the criteria-derived posttest odds of pPD were a significant predictor of conversion at follow-up. The updated criteria performed similarly to the original but showed a slight increase in sensitivity. CONCLUSIONS: The new criteria demonstrated suboptimal sensitivity in our random sample of community-dwelling individuals. The absence of specialized assessments with high likelihood ratios in our cohort could be hindering the demonstration of higher sensitivities. Such assessments should be a part of future validation attempts. © 2020 International Parkinson and Movement Disorder Society.

Qualitative Research in Veterinary Medical Education: Part 1-Principles of Qualitative Design.

Qualitative methodologies are relative newcomers to health sciences education research. While they may look very different to their quantitative counterparts in terms of size and scope, when well-applied they offer a fresh perspective and generate valuable research findings. Although qualitative research is being increasingly conducted in veterinary medical education, there are few contextualized resources to assist those who would like to develop their expertise in this area. In this article, we address this by introducing the principles of qualitative research design in a veterinary medical education context. Drawing from a range of contemporary resources, we explore the types of research goals and questions that are amenable to qualitative inquiry and discuss the process of formulating a worthwhile research question. We explain what research paradigms are and introduce readers to some of the methodological options available to them in qualitative research. Examples from veterinary medical education are used to illustrate key points. In a second companion article, we will focus on the decisions that need to be made regarding data sampling, collection, and analysis. We will also consider how qualitative research is evaluated, and discuss how qualitative findings are applied. Taken together, the two articles build an understanding of qualitative research, illuminate its potential to contribute to the scholarship of teaching and learning in veterinary medical education, and equip readers with an improved capacity to appraise its value.

Application of the movement disorder society prodromal Parkinson's disease research criteria in 2 independent prospective cohorts.

BACKGROUND: The research criteria for prodromal PD of the MDS propose a new approach for the assessment of the individual probability of prodromal PD. These criteria require a testing of their reliability in different prospective cohorts. OBJECTIVES: The objective was to evaluate the MDS prodromal PD criteria in 2 independent prospective studies. METHODS: Prodromal PD probabilities of the Tübingen Evaluation of Risk Factors for Early Detection of Neurodegeneration cohort (TREND study, n = 650, recruited by the presence of probable rapid eye movement sleep behavior disorder, depression, and/or hyposmia or none of these at baseline and 2-, 4-, and 6-year follow-up) and the population-based Prospective Evaluation of Risk Factors for Idiopathic Parkinson's Syndrome cohort (PRIPS Tübingen subsample; n = 715, baseline and 3- and 5-year follow-up) were calculated. Baseline posttest probabilities, time to PD diagnosis, marker constellations, and longitudinal changes of prodromal PD probabilities were analyzed. RESULTS: Incident PD cases (TREND, n = 10; PRIPS = 7) showed significantly higher likelihood ratios of risk and prodromal markers at baseline when compared with nonconverters. Only 2 of 17 incident PD cases met the criteria for probable prodromal PD (ie, posttest probability > 80%) and 5 had possible prodromal PD (ie, > 50%) 1.4 to 3.8 years before diagnosis. The criteria showed high specificity and negative predictive values (>98%), but low sensitivity (TREND, 30%; PRIPS, 14%) and positive predictive values (TREND, 19%, PRIPS, 50%). The individual risk for prodromal PD in incident PD cases showed an inverse correlation with the time to conversion (Spearman rho = .80, P = .006) and unlike in nonconverters, increased during follow-up. CONCLUSION: The MDS prodromal criteria provide a practical framework for the calculation of prodromal PD risk. Although specificity of the criteria is high, most patients will not meet the criteria before diagnosis unless testing is thoroughly performed with numerous and highly specific markers objectively assessed. © 2017 International Parkinson and Movement Disorder Society.

A conceptual framework for research on subjective cognitive decline in preclinical Alzheimer's disease.

There is increasing evidence that subjective cognitive decline (SCD) in individuals with unimpaired performance on cognitive tests may represent the first symptomatic manifestation of Alzheimer's disease (AD). The research on SCD in early AD, however, is limited by the absence of common standards. The working group of the Subjective Cognitive Decline Initiative (SCD-I) addressed this deficiency by reaching consensus on terminology and on a conceptual framework for research on SCD in AD. In this publication, research criteria for SCD in pre-mild cognitive impairment (MCI) are presented. In addition, a list of core features proposed for reporting in SCD studies is provided, which will enable comparability of research across different settings. Finally, a set of features is presented, which in accordance with current knowledge, increases the likelihood of the presence of preclinical AD in individuals with SCD. This list is referred to as SCD plus.

Pain and Associated Neuropsychiatric Symptoms in Patients Suffering from Dementia: Challenges at Different Levels and Proposal of a Conceptual Framework.

Old age is critically associated with multi-morbidity, chronic pain, and high risk for dementia. Recognizing and treating pain is very much dependent on language comprehension and production. Both may be impaired in dementia. Moreover, neuropsychiatric symptoms may interact with pain perception. The main aims of the present article were 1) to identify key areas for future research to elucidate the relation between pain and associated neuropsychiatric symptoms in dementia, and 2) to provide a conceptual framework for ameliorating the clinical process of recognizing, assessing, and managing pain in non-communicating patients with advanced dementia.

Comparison in detection of prodromal Parkinson's disease patients using original and updated MDS research criteria in two independent cohorts.

INTRODUCTION: MDS research criteria for prodromal Parkinson's disease (pPD) were published in 2015 and updated in 2019. We aimed to determine the difference in pPD patient detection rates in two cohorts recruited via gastrointestinal symptoms (PARCAS study) and the presence of a probable REM sleep behaviour disorder (PDBIOM study) using the original and updated criteria. METHODS: We evaluated all risk and prodromal markers, except genetic testing, plasma urate and physical inactivity, in both cohorts and DaT scan, diabetes mellitus type II and cognitive deficit in the PARCAS cohort. Thresholds of 50% probability for possible pPD and 80% for probable pPD were used. RESULTS: PPD status as identified by the original/updated criteria showed differences for probable pPD (n = 8/9; original/updated criteria) and possible pPD (n = 9/13) in the PARCAS cohort (total n = 158), as well as for probable pPD (n = 19/21) and possible pPD (n = 6/3) in the PDBIOM cohort (total n = 48). A high concordance rate was found between the two criteria sets (p < 0.001 for all groups). CONCLUSION: All probable pPD cases remained in the same category after evaluation with both criteria; three possible pPD cases based on the original criteria exceeded the threshold for probable pPD based on the updated criteria, and five possible new pPD cases were detected, with only one shift in the opposite direction. The updated MDS pPD research criteria tend to identify more patients as positive, yet their accuracy needs to be determined in prospective studies.

Research diagnostic criteria for Alzheimer's disease: findings from the LipiDiDiet randomized controlled trial.

BACKGROUND: To explore the utility of the International Working Group (IWG)-1 criteria in recruitment for Alzheimer's disease (AD) clinical trials, we applied the more recently proposed research diagnostic criteria to individuals enrolled in a randomized controlled prevention trial (RCT) and assessed their disease progression. METHODS: The multinational LipiDiDiet RCT targeted 311 individuals with IWG-1 defined prodromal AD. Based on centrally analyzed baseline biomarkers, participants were classified according to the IWG-2 and National Institute on Aging-Alzheimer's Association (NIA-AA) 2011 and 2018 criteria. Linear mixed models were used to investigate the 2-year change in cognitive and functional performance (Neuropsychological Test Battery NTB Z scores, Clinical Dementia Rating-Sum of Boxes CDR-SB) (criteria × time interactions; baseline score, randomization group, sex, Mini-Mental State Examination (MMSE), and age also included in the models). Cox models adjusted for randomization group, MMSE, sex, age, and study site were used to investigate the risk of progression to dementia over 2 years. RESULTS: In total, 88%, 86%, and 69% of participants had abnormal cerebrospinal fluid (CSF) ß-amyloid, total tau, and phosphorylated tau, respectively; 64% had an A+T+N+ profile (CSF available for N = 107). Cognitive-functional decline appeared to be more pronounced in the IWG-2 prodromal AD, NIA-AA 2011 high and intermediate AD likelihood, and NIA-AA 2018 AD groups, but few significant differences were observed between the groups within each set of criteria. Hazard ratio (95% CI) for dementia was 4.6 (1.6-13.7) for IWG-2 prodromal AD (reference group no prodromal AD), 7.4 (1.0-54.7) for NIA-AA 2011 high AD likelihood (reference group suspected non-AD pathology SNAP), and 9.4 (1.2-72.7) for NIA-AA 2018 AD (reference group non-Alzheimer's pathologic change). Compared with the NIA-AA 2011 high AD likelihood group (abnormal ß-amyloid and neuronal injury markers), disease progression was similar in the intermediate AD likelihood group (medial temporal lobe atrophy; no CSF available). CONCLUSIONS: Despite being less restrictive than the other criteria, the IWG-1 criteria reliably identified individuals with AD pathology. More pragmatic and easily applicable selection criteria might be preferred due to feasibility in certain situations, e.g., in multidomain prevention trials that do not specifically target ß-amyloid/tau pathologies. TRIAL REGISTRATION: Netherlands Trial Register, NL1620 . Registered on 9 March 2009.

[From autism spectrum to autism constellation]. / Del espectro autista a la constelación autista.

Research on autism and mental disorders has been unsuccessful over the past few decades, as can be inferred from the poor results related to advances in other diseases. It is concerning that, after more than a half century of research based on the Diagnostic and Statistical Manual of Mental Disorders (DSM), no biological markers have been found to prove the validity of the DSM mental disorders. Criticisms to DSM have been focused mainly on the categorical conceptualization, false comorbidity and the polythetic nature of diagnostic criteria. The lack of validity of the DSM model requests for a change in research designs, in order to overcome the problems derived from a paradigm that has stopped to be productive. In the field of clinical practice, it is even more pressing a change of mindset in order to incorporate the heterogeneity of endophenotypes that overflows the classification of the DSM, to adopt a dimensional perspective of mental problems and to develop an alternative interpretation for comorbidity. Related to research are suggested designs based on Domain Research Criteria and a multifactorial analysis with very large samples (big data). For clinical practice it is suggested a dimensional approach based on the specificities of each person with autism.

La investigación sobre el autismo, y sobre los trastornos mentales en general, ha sido poco fructífera durante las últimas décadas, como se desprende de los escasos resultados obtenidos en comparación con los avances en otras enfermedades. Preocupa que, tras más de medio siglo de investigación basada en el Diagnostic and Statistical Manual of Mental Disorders (DSM), no se hayan encontrado marcadores biológicos que acrediten la validez de los trastornos mentales que lo configuran. Las críticas al DSM, todas ellas aplicables al autismo, se han centrado principalmente en la conceptualización categórica, en la falsa comorbilidad y en el carácter politético de los criterios diagnósticos. La falta de validez del modelo del DSM insta a un cambio en los diseños de investigación, con el fin de superar el bloqueo derivado de un paradigma que ha dejado de ser productivo. En el terreno de la práctica clínica resulta, incluso más apremiante, un cambio de mentalidad que permita: incorporar la heterogeneidad de endofenotipos que desbordan la clasificación del DSM, adoptar una perspectiva dimensional de los problemas mentales y desarrollar una interpretación alternativa de la comorbilidad Con referencia a la investigación, se proponen diseños basados en criterios de investigación por dominios (Research Domain Criteria) y en análisis multifactoriales con muestras muy grandes (big data). Por lo que respecta a práctica clínica se sugiere un enfoque dimensional basado en las especificidades de cada persona con autismo, lo cual desborda el patrón clínico del espectro.

Prodromal Parkinson disease in patients with idiopathic hyposmia.

BACKGROUND: Idiopathic hyposmia (IH) is a prodromal marker of Parkinson disease (PD). However, IH is common in the general population and only a minority will develop PD. Identification of individuals with IH at prodromal stage of PD would serve to select them to implement neuroprotective agents, when available. OBJECTIVE: To identify prodromal PD in IH patients using the Movement Disorders Society (MDS) research criteria for prodromal PD. METHODS: We applied the MDS research criteria for prodromal PD to 25 consecutive patients older than 50 years who were self-referred for smell loss and had IH, and to 18 controls. A number of risk and prodromal PD markers were assessed in all participants including REM sleep behavior disorder (RBD) by video-polysomnography and nigrostriatal dopaminergic dysfunction by DAT-SPECT. After follow-up of 4.7 ± 2.2 years, participants were re-assessed to look for incident PD. RESULTS: Prodromal PD probability was higher in patients than in controls (19.45 ± 34.9% versus 1.74 ± 4.48%; p = 0.019). Four (16%) patients met the criteria of prodromal PD surpassing 80% probability (99.8%, 99.5%, 88.3%, 86.4%). Three (12%) patients had RBD and four (16%) abnormal DAT-SPECT. At the end of follow-up, one (4%) IH patient who had RBD and baseline prodromal PD probability of 86.4% developed PD, while all controls remained disease free. CONCLUSIONS: Prodromal PD is infrequent among IH patients. MDS research criteria for prodromal PD are useful to identify a subgroup of IH patients at high risk of PD when RBD is assessed by video-polysomnography and nigrostriatal dopamine deficiency with DAT-SPECT.

"Atypical" atypical parkinsonism: Critical appraisal of a cohort.

BACKGROUND: Atypical parkinsonian conditions such as multiple system atrophy (MSA), progressive supranuclear palsy (PSP), corticobasal syndrome (CBS) and Dementia with Lewy bodies (DLB) comprise 10-15% of parkinsonian syndromes. Misdiagnosis with Parkinson disease (PD) and within the entities is common, given the absence of reliable biomarkers. However a correct diagnosis is not only important in clinical practice, but also crucial for any trial attempting to identify biomarkers or new treatments. METHODS: Consecutive patients, who were referred to our tertiary center with a diagnosis of a particular AP were included and the medical records were reviewed retrospectively. We applied each set of current diagnostic research criteria to the respective cohort to see which features fit in and if there are any additional atypical features "outside" the classic definition. RESULTS: Sixty-nine patients were recruited between January 2013 and May 2015 clinically presenting with one of the following phenotypes: 14 MSA, 24 PSP, 19 CBS and 12 DLB. Up to 49% showed additional "atypical" features and approximately 10% eventually received an alternative diagnosis, in half of whom this being based on genetic testing. CONCLUSIONS: In a subset of our patients, despite the final diagnosis of an AP being maintained, there were additional "atypical" features. It remains to be seen if these reflect the clinical heterogeneity of APs, or should prompt a search for an alternative diagnosis. The search for biomarkers is more likely to be successful in homogenous groups of "typical" patients, hence the importance of recognizing "atypical" features.

Clinical and Research Criteria for Developmental Coordination Disorder-Should They Be One and the Same?

The aim of this paper is to discuss if criteria used for diagnosing children for clinical purposes should be the same as for the selection of children with Developmental Coordination Disorder for research. Next, we give an overview of the criteria mentioned in the development of the European guideline for diagnosing Developmental Coordination Disorder and the implementation of this guideline in different countries. To gain insight into current clinical practice, we also reviewed the medical files of children attending rehabilitation centers for the criteria used to diagnose Developmental Coordination Disorder in the Netherlands. To conclude, we state our expert opinion on why and when research and clinical criteria for Developmental Coordination Disorder should or should not be the same.

Del espectro autista a la constelación autista / From autism spectrum to autism constellation

La investigación sobre el autismo, y sobre los trastornos mentales en general, ha sido poco fructífera durante las últimas décadas, como se desprende de los escasos resultados obtenidos en comparación con los avances en otras enfermedades. Preocupa que, tras más de medio siglo de investigación basada en el Diagnostic and Statistical Manual of Mental Disorders (DSM), no se hayan encontrado marcadores biológicos que acrediten la validez de los trastornos mentales que lo configuran. Las críticas al DSM, todas ellas aplicables al autismo, se han centrado principalmente en la conceptualización categórica, en la falsa comorbilidad y en el carácter politético de los criterios diagnósticos. La falta de validez del modelo del DSM insta a un cambio en los diseños de investigación, con el fin de superar el bloqueo derivado de un paradigma que ha dejado de ser productivo. En el terreno de la práctica clínica resulta, incluso más apremiante, un cambio de mentalidad que permita: incorporar la heterogeneidad de endofenotipos que desbordan la clasificación del DSM, adoptar una perspectiva dimensional de los problemas mentales y desarrollar una interpretación alternativa de la comorbilidad Con referencia a la investigación, se proponen diseños basados en criterios de investigación por dominios (Research Domain Criteria) y en análisis multifactoriales con muestras muy grandes (big data). Por lo que respecta a práctica clínica se sugiere un enfoque dimensional basado en las especificidades de cada persona con autismo, lo cual desborda el patrón clínico del espectro.

Research on autism and mental disorders has been unsuccessful over the past few decades, as can be inferred from the poor results related to advances in other diseases. It is concerning that, after more than a half century of research based on the Diagnostic and Statistical Manual of Mental Disorders (DSM), no biological markers have been found to prove the validity of the DSM mental disorders. Criticisms to DSM have been focused mainly on the categorical conceptualization, false comorbidity and the polythetic nature of diagnostic criteria. The lack of validity of the DSM model requests for a change in research designs, in order to overcome the problems derived from a paradigm that has stopped to be productive. In the field of clinical practice, it is even more pressing a change of mindset in order to incorporate the heterogeneity of endophenotypes that overflows the classification of the DSM, to adopt a dimensional perspective of mental problems and to develop an alternative interpretation for comorbidity. Related to research are suggested designs based on Domain Research Criteria and a multifactorial analysis with very large samples (big data). For clinical practice it is suggested a dimensional approach based on the specificities of each person with autism.