Protective effect of bilingualism on aging, MCI, and dementia: A community-based study.

INTRODUCTION: Lifelong bilingualism is associated with a delayed age at onset of dementia, but evidence from community-based studies is limited. We investigated the relationship between bilingualism and the prevalence of cognitive impairment in a linguistically diverse community. METHODS: A door-to-door community study was conducted from January to December 2021 in urban Bengaluru, India. 1234 individuals aged ≥60 years participated in the study. Participants were diagnosed with no cognitive impairment (NCI), mild cognitive impairment (MCI), or dementia using established diagnostic criteria. RESULTS: Dementia prevalence was higher in monolinguals (4.9%) than bilinguals (0.4%) (P = .001). The prevalence of MCI was also higher in monolinguals (8.5%) than bilinguals (5.3%) (P = .001). The study also revealed better cognitive function in bilinguals than monolinguals with NCI, after controlling for confounding variables. DISCUSSION: The current study provides significant support for the protective effect of bilingualism on cognitive impairment in an urban community with extensive bilingual interactional contexts in everyday life. HIGHLIGHTS: Bilingualism has been demonstrated to protect against dementia and mild cognitive impairment in a linguistically diverse community with extensive code-switching contexts. Bilingual older individuals had superior baseline cognitive performance compared to monolingual older individuals. Bilingualism was found to have an independent effect on general cognition after adjusting for major social determinants of health in the group without cognitive impairment.

Illiterate Addenbrooke's Cognitive Examination-III in Three Indian Languages: An Adaptation and Validation Study.

BACKGROUND: Literacy is an important factor that predicts cognitive performance. Existing cognitive screening tools are validated only in educated populations and are not appropriate for older adults with little or no education leading to poor performance on these tests and eventually leading to misdiagnosis. This challenge for clinicians necessitates a screening tool suitable for illiterate or low-literate older individuals. OBJECTIVES: The objective was to adapt and validate Addenbrooke's Cognitive Examination-III (ACE-III) for screening general cognitive functions in illiterate and low-literate older populations in the Indian context in three languages. METHOD: The Indian illiterate ACE-III was systematically adapted by modifying the original items of the Indian literate ACE-III to assess the cognitive functions of illiterates and low-literates with the consensus of an expert panel of professionals working in the area of dementia and related disorders. A total of 180 illiterate or low-literate participants (84 healthy-controls, 50 with dementia, and 46 with mild cognitive impairment [MCI]) were recruited from three different centers speaking Bengali, Hindi, and Kannada to validate the adapted version. RESULTS: The optimal cut-off score for illiterate ACE-III to distinguish controls from dementia in all 3 languages was 75. The optimal cut-off scores in distinguishing between controls and MCI ranged from 79 to 82, with a sensitivity ranging from 93% to 99% and a specificity ranging from 72% to 99%. CONCLUSION: The test is found to have good psychometric properties and is a reliable cognitive screening tool for identifying dementia and MCI in older adults with low educational backgrounds in the Indian context.

MoCA in five Indian languages: A brief screening tool to diagnose dementia and MCI in a linguistically diverse setting.

INTRODUCTION AND OBJECTIVES: Early dementia diagnosis in low and middle-income countries (LMIC) is challenging due to limited availability of brief, culturally appropriate, and psychometrically validated tests. Montreal Cognitive Assessment (MoCA) is one of the most widely used cognitive screening tests in primary and secondary care globally. In the current study, we adapted and validated MoCA in five Indian languages (Hindi, Bengali, Telugu, Kannada, and Malayalam) and determined the optimal cut-off points that correspond to screening for clinical diagnosis of dementia and MCI. METHODS: A systematic process of adaptation and modifications of MoCA was fulfilled. A total of 446 participants: 214 controls, 102 dementia, and 130 MCI were recruited across six centers. RESULTS: Across five languages, the area under the curve for diagnosis of dementia varied from 0.89 to 0.98 and MCI varied from 0.73 to 0.96. The sensitivity, specificity and optimum cut-off scores were established separately for five Indian languages. CONCLUSIONS: The Indian adapted MoCA is standardized and validated in five Indian languages for early diagnosis of dementia and MCI in a linguistically and culturally diverse population.

Picture-naming test for a linguistically diverse population with cognitive impairment and dementia.

BACKGROUND: Picture-naming tests (PNTs) evaluate linguistic impairment in dementia due to semantic memory impairment, impaired lexical retrieval or perceptual deficits. They also assess the decline in naming impairment at various stages of dementia and mild cognitive impairment (MCI) that occurs due to progressive cognitive impairment. With the increasing numbers of people with dementia globally, it is necessary to have validated naming tests and norms that are culturally and linguistically appropriate. AIMS: In this cross-sectional study we harmonized a set of 30 images applicable to the Indian context across five languages and investigated the picture-naming performance in patients with MCI and dementia. METHODS & PROCEDURES: A multidisciplinary expert group formed by the Indian Council of Medical Research (ICMR) collaborated towards developing and adapting a picture naming test (PNT) known as the ICMR-PNT in five Indian languages: Hindi, Bengali, Telugu, Kannada and Malayalam. Based on cross-cultural adaptation guidelines and item-wise factor analysis and correlations established separately across five languages, the final version of the ICMR-PNT test was developed. A total of 368 controls, 123 dementia and 128 MCI patients were recruited for the study. Psychometric properties of the adapted version of the ICMR-PNT were examined, and sensitivity and specificity were examined. OUTCOMES & RESULTS: The ICMR-PNT scores in all languages combined were higher in controls compared with patients with dementia and MCI (F2, 615 = 139.85; p < 0.001). Furthermore, PNT scores for MCI was higher in comparison with patients with dementia in all languages combined (p < 0.001). The area under the curve across the five languages ranged from 0.81 to 1.00 for detecting dementia. There was a negative correlation between Clinical Dementia Rating (CDR) and ICMR-PNT scores and a positive correlation between Addenbrooke's Cognitive Examination-III (ACE-III) and ICMR-PNT scores in control and patient groups. CONCLUSIONS & IMPLICATIONS: The ICMR-PNT was developed by following cross-cultural adaptation guidelines and establishing correlations using item-wise factor analysis across five languages. This adapted PNT was found to be a reliable tool when assessing naming abilities effectively in mild to moderate dementia in a linguistically diverse context. WHAT THIS PAPER ADDS: What is already known on this subject Picture-naming evaluates language impairment linked to naming difficulties due to semantic memory, lexical retrieval or perceptual disturbances. As a result, picture naming tests (PNTs) play an important role in the diagnosis of dementia. In a heterogeneous population such as India, there is a need for a common PNT that can be used across the wide range of languages. What this study adds to existing knowledge PNTs such as the Boston Naming Test (BNT) were developed for the educated, mostly English-speaking, Western populations and are not appropriate for use in an Indian context. To overcome this challenge, a PNT was harmonized in five Indian languages (Hindi, Bengali, Telugu, Kannada and Malayalam) and we report the patterns of naming difficulty in patients with MCI and dementia. The ICMR-PNT demonstrated good diagnostic accuracy when distinguishing patients with mild to moderate dementia from cognitively normal individuals. What are the potential or actual clinical implications of this work? With the growing number of persons suffering from Alzheimer's disease and other forms of dementia around the world, its critical to have culturally and linguistically relevant naming tests and diagnosis. This validated ICMR-PNT can be used widely as a clinical tool to diagnose dementia and harmonize research efforts across diverse populations.

Cognition, Behavior, and Caregiver Stress in Dementia during the COVID-19 Pandemic: An Indian Perspective.

OBJECTIVES: Little is known regarding the cognitive and behavioral status of patients with dementia and their caregivers in lower middle-income countries during the COVID-19 pandemic. This study aimed to understand the impact of the pandemic on persons with dementia and their caregivers in India. METHODS: This was an observational study. A cohort of 66 persons with dementia and their caregivers were evaluated during the COVID-19 pandemic in 2 specialist hospitals in South India. Caregivers were interviewed at 2 distinct time points of the pandemic: during the national lockdown and 5 months after during later periods of the "cluster of cases" transmission phase. Participants were assessed via telephone utilizing validated instruments (Neuropsychiatric Inventory [NPI], Clinical Dementia Rating [CDR] Scale, and Depression, Anxiety and Stress Scale [DASS-21]) and a semi-structured questionnaire. The questionnaire documented sociodemographic information, clinical history, infection measures adopted, changes in caregiving routines, involvement in functional rehabilitation activities, and access to medical and long-term care support services. RESULTS: The 2-phase follow-up study found a significant worsening of behavior in dementia patients, demonstrated by a difference in the NPI sub-domain scores for anxiety (mean difference [standard deviation, SD] = -0.552 [1.993], t58 = -2.109, p = 0.039) and eating disturbances (mean difference [SD] = -1.121 [2.493], t59 = -3.424, p = 0.001). A relatively high proportion of patients developed anxiety (cumulative incidence = 24.53%) and eating disturbances (cumulative incidence = 26.92%), without having these symptoms at baseline. There was a trend toward an increase in proportion of persons with severe dementia (19.7% vs. 39.4%) on follow-up. Caregiver distress reported was significantly associated with neuropsychiatric symptoms (r = 0.712, p < 0.001) and dementia severity (ρ = 0.365, p = 0.004). In addition, difficulties in accessing medical care persisted between the 2 assessments, and there were statistically significant differences between functional rehabilitation activities such as indoor activities (p < 0.001), outdoor activities (p = 0.013), and physical exercises (p = 0.003) between baseline and follow-up. CONCLUSION: Findings suggest interruption of functional rehabilitation activities and disruption in medical care services are likely to have had an adverse impact on patients with dementia and contributed toward caregiver distress.

Experiences of people with dementia and their caregivers during the COVID-19 pandemic in India: A mixed-methods study.

BACKGROUND: The COVID-19 pandemic has unprecedented consequences for the management of chronic diseases such as dementia. However, limited evidence exists on the condition of persons with dementia and their caregivers during the pandemic in lower-middle-income countries (LMICs). The study aimed to provide insights into the experiences of persons with dementia and their families during the early phases of the pandemic in India. METHODS: This study adopted a mixed-method approach. One hundred and four persons with dementia and their caregivers were evaluated via telephone using validated instruments and a semi-structured interview guide. We used the quantitative data collected to establish a baseline, whereas qualitative data were analysed thematically. RESULTS: The study revealed that persons with dementia and their caregivers experienced difficulties during the pandemic, which included worsening of behaviour, problems in accessing care, disruptions in functional activities and struggles in enforcing infection prevention contributing to caregiver distress. An important finding that emerged was the unchanging reality of caregiving for families. The relative success of the public health response to the COVID-19 pandemic contrasted with the lack of awareness and formal support for dementia. CONCLUSIONS: The COVID-19 pandemic has exposed the vulnerabilities of persons with dementia and their caregivers. This calls for a collaborative reframing of medical care and public health policies to address dementia care.

Semantic memory impairment in dementia: A cross-cultural adaptation study.

BACKGROUND: Semantic memory deficits are frequently encountered in dementia and distinct patterns of semantic impairment characterize the subtypes of dementia. Life course and cultural experiences significantly influence semantic memory. Hence, there is a need to assess semantic memory using culturally appropriate tests, to aid accurate diagnosis of dementia and facilitate cross-cultural collaborative research. AIMS: In this prospective study, we adapted and validated the Cambridge Semantic Memory (CSM) test battery to the Indian cultural context and studied the patterns of semantic memory impairment across dementia subtypes. METHODS: The CSM battery was modified using standard methods and by incorporating culturally appropriate changes and new semantic categories relevant to India. The adapted Indian Semantic Memory (ISM) test battery was administered to a cohort of 121 subjects, consisting of controls and dementia: Alzheimer's disease (AD), progressive non-fluent aphasia (PNFA), semantic dementia (SD), and behavioral variant fronto-temporal dementia (BvFTD). Profile of semantic memory performance across groups was examined. RESULTS: The ISM battery was found to be a valid measure of semantic memory. The novel semantic categories of gods/religious icons, vegetables, and food items added value to the diagnostic process. Distinct semantic memory profiles in SD, PNFA, AD, and BvFTD were demonstrated. CONCLUSIONS: The cultural adaptation of a semantic memory battery for the Indian context provided sensitive evidence of semantic memory impairment in dementia and its subtypes. The clinical and research application of the ISM battery will enhance diagnostic evaluation that can aid in early and accurate identification of deficits and devising intervention strategies and enable research across cultures.

Evaluation of Vascular Cognitive Impairment Using the ICMR-Neuro Cognitive Tool Box (ICMR-NCTB) in a Stroke Cohort from India.

Background and Purpose: Vascular cognitive impairment (VCI) presents with a spectrum of cognitive impairment due to stroke and poses a huge socioeconomic burden especially in low middle-income countries. There is a critical need for early recognition and identification of VCI patients. Therefore, we developed and validated culturally appropriate neuropsychological instruments, the ICMR-Neuro Cognitive Tool-Box (ICMR-NCTB) and Montreal Cognitive Assessment (MoCA) to diagnose vascular MCI and dementia in the Indian context. Methods: A total of 181 participants: 59 normal cognition, 25 stroke with normal cognition, 46 vascular MCI (VaMCI) and 51 vascular dementia (VaD) were recruited for the study. The ICMR-NCTB and MoCA were administered to patients with VCI and major cognitive domains were evaluated. Results: The ICMR-NCTB was found to have good internal reliability in VaMCI and VaD. The sensitivity of the ICMR-NCTB to detect VaMCI and VaD ranged from 70.8% to 72.9% and 75.9% to 79.7%, respectively, and the specificity for VaMCI and VaD ranged from 84.8% to 86.1% and 82.5% to 85.2%, respectively. The MoCA had excellent sensitivity and specificity to detect VaMCI and VaD at ideal cut-off scores. Conclusion: The ICMR-NCTB is a valid neuropsychological toolbox that can be used for comprehensive cognitive assessment and diagnosis of VCI in India. In addition, the Indian version of MoCA is more adept as a screening instrument to detect VCI due to its high sensitivity. The ICMR-NCTB will aid in early detection and management of many patients, thereby reducing the burden of vascular MCI and dementia in India.

Validation of ICMR Neurocognitive Toolbox for Dementia in the Linguistically Diverse Context of India.

Objectives: The growing prevalence of dementia, especially in low- and middle-income countries (LMICs), has raised the need for a unified cognitive screening tool that can aid its early detection. The linguistically and educationally diverse population in India contributes to challenges in diagnosis. The present study aimed to assess the validity and diagnostic accuracy of the Indian Council of Medical Research-Neurocognitive Toolbox (ICMR-NCTB), a comprehensive neuropsychological test battery adapted in five languages, for the diagnosis of dementia. Methods: A multidisciplinary group of experts developed the ICMR-NCTB based on reviewing the existing tools and incorporation of culturally appropriate modifications. The finalized tests of the major cognitive domains of attention, executive functions, memory, language, and visuospatial skills were then adapted and translated into five Indian languages: Hindi, Bengali, Telugu, Kannada, and Malayalam. Three hundred fifty-four participants were recruited, including 222 controls and 132 dementia patients. The sensitivity and specificity of the adapted tests were established for the diagnosis of dementia. Results: A significant difference in the mean (median) performance scores between healthy controls and patients with dementia was observed on all tests of ICMR-NCTB. The area under the curve for majority of the tests included in the ICMR-NCTB ranged from 0.73 to 1.00, and the sensitivity and specificity of the ICMR-NCTB tests ranged from 70 to 100% and 70.7 to 100%, respectively, to identify dementia across all five languages. Conclusions: The ICMR-NCTB is a valid instrument to diagnose dementia across five Indian languages, with good diagnostic accuracy. The toolbox was effective in overcoming the challenge of linguistic diversity. The study has wide implications to address the problem of a high disease burden and low diagnostic rate of dementia in LMICs like India.

Role of Autoantibodies in Neurodegenerative Dementia: An Emerging Association.

OBJECTIVE: In the background of an emerging role for immune dysregulation in neurodegenerative dementias, this study aimed to investigate the relationship between systemic autoimmunity and dementia. The objective was to study the frequency and profile of disease-specific autoantibodies in Alzheimer's dementia (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB). METHODS: Immunological testing was performed in a large cohort of neurodegenerative dementia diagnosed based on standard clinical and imaging criteria. Patients were evaluated for the presence of autoantibodies specific for systemic autoimmune diseases that included anti-extractable nuclear antibody profile, rheumatoid factor antibody (RA), perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA), and cytoplasmic anti-neutrophil cytoplasmic antibody (c-ANCA) in serum. RESULTS: Of 174 patients with degenerative dementia (FTD = 114, AD = 53, and DLB = 7) evaluated with immunological testing, 18.9% (n = 33) were seropositive for autoantibodies. The common antibodies detected were anti-Scl-70 (25%), anti-Ro-52 (18.7%), anti-nRNP-Sm (12.5%), and anti-CENP-B (9.3%). There were no significant systemic complaints in the majority of patients. A wider range of antibodies were positive in FTD compared to AD and DLB. While no difference was observed in the mean age, sex, or duration of illness between seropositive and negative patients, family history of dementia was more frequent among seronegative patients. CONCLUSION: Our findings indicate an emerging role for immune dysregulation in patients with classical neurodegenerative dementias, especially those with FTD. These autoantibodies could play a role in immune degradation of protein aggregates that characterize neurodegeneration. Study findings emphasize the need to explore the complex relationship between systemic autoimmunity and neurodegenerative dementia.

Bilingualism and Its Implications for Neuropsychological Evaluation.

OBJECTIVE: In the background of a large population of bilinguals globally, the study aimed to develop standards of neuropsychological testing in the context of bilingualism. Because bilingualism is known to affect cognitive processes, bilinguals and monolinguals were compared on their performance on cognitive tests, to investigate the possibility of the need for separate normative data for the two groups. METHOD: A comprehensive neuropsychological test battery, standardized across five Indian languages: the Indian Council of Medical Research-Neuro Cognitive Tool Box (ICMR-NCTB) was administered to 530 participants (267 monolingual and 263 bilinguals matched for age and education). A systematic method of testing cognition in bilinguals was developed; to identify the appropriate language for testing, ensure language proficiency of examiner, and to interpret the bilingual responses. Additionally, the performance of bilinguals on the ICMR-NCTB was compared with monolinguals. RESULTS: Cognitive testing in the bilingual context was performed in the most proficient language of the participants, by examiners well versed with the language. Results from the language-based tests suggested that the frequent occurrence of borrowed- and language-mixed words required consideration while scoring. The reported bilingual effect on cognitive processes did not reflect as differences in the performance between bilinguals and monolinguals. CONCLUSIONS: Observations from the study provide robust recommendations for neuropsychological testing in the context of bilingualism. Results indicate that separate normative data may not be required for bilinguals and monolinguals. The study will be relevant and provide a reference framework to address similar issues in the large population of bilinguals in other societies.

A Screening Tool to Detect Stroke Aphasia: Adaptation of Frenchay Aphasia Screening Test (FAST) to the Indian Context.

BACKGROUND: Aphasia is a common consequence of stroke. To optimize recovery, it becomes critical as there are early identification and treatment of language deficits. The rising burden of stroke aphasia and lack of screening tools in the Indian context necessitates the need for a screening tool. OBJECTIVE: We aimed to adapt and validate the Frenchay Aphasia Screening Test (FAST) to the Indian context in two widely spoken Indian languages, Telugu and Kannada, for the literate and illiterate population. METHODS: A systematic process of adaptation and culturally appropriate modifications of the original FAST were done in 116 healthy controls and 115 patients. The validity of the adapted test was established. RESULTS: The optimum cut-off values for detecting aphasia in our sample ranged from 25 to 25.5 (literate) and 13.5 to 15.5 (illiterate) with high sensitivity and specificity. There was also a significant correlation between aphasia scores for adapted FAST and the Western Aphasia Battery (WAB), establishing good convergent validity. DISCUSSION: Results of the adaptation and validation of two Indian versions of FAST, suggest that it is an easy-to-use screening measure for detecting stroke-related language disabilities. The psychometric properties of the Indian version of FAST met the standardised requirements for adaptation and validation. CONCLUSIONS: The Indian version of FAST was found to be a reliable and valid bedside screening tool for aphasia in stroke patients. We aim that this study will facilitate the use of the test across other Indian languages and a large clinical population in the future.

Validation of Indian Council of Medical Research Neurocognitive Tool Box in Diagnosis of Mild Cognitive Impairment in India: Lessons from a Harmonization Process in a Linguistically Diverse Society.

BACKGROUND/AIMS: In a linguistically diverse country such as India, challenges remain with regard to diagnosis of early cognitive decline among the elderly, with no prior attempts made to simultaneously validate a comprehensive battery of tests across domains in multiple languages. This study aimed to determine the utility of the Indian Council of Medical Research-Neurocognitive Tool Box (ICMR-NCTB) in the diagnosis of mild cognitive impairment (MCI) and its vascular subtype (VaMCI) in 5 Indian languages. METHODS: Literate subjects from 5 centers across the country were recruited using a uniform process, and all subjects were classified based on clinical evaluations and a gold standard test protocol into normal cognition, MCI, and VaMCI. Following adaptation and harmonization of the ICMR-NCTB across 5 different Indian languages into a composite Z score, its test performance against standards, including sensitivity and specificity of the instrument as well as of its subcomponents in diagnosis of MCI, was evaluated in age and education unmatched and matched groups. RESULTS: Variability in sensitivity-specificity estimates was noted between languages when a total of 991 controls and 205 patients with MCI (157 MCI and 48 VaMCI) were compared due to a significant impact of age, education, and language. Data from a total of 506 controls, 144 patients with MCI, and 46 patients with VaMCI who were age- and education-matched were compared. Post hoc analysis after correction for multiple comparisons revealed better performance in controls relative to all-cause MCI. An optimum composite Z-score of -0.541 achieved a sensitivity of 81.1% and a specificity of 88.8% for diagnosis of all-cause MCI, with a high specificity for diagnosis of VaMCI. Using combinations of multiple-domain 2 test subcomponents retained a sensitivity and specificity of >80% for diagnosis of MCI. CONCLUSIONS: The ICMR-NCTB is a "first of its kind" approach at harmonizing neuropsychological tests across 5 Indian languages for the diagnosis of MCI due to vascular and other etiologies. Utilizing multiple-domain subcomponents also retains the validity of this instrument, making it a valuable tool in MCI research in multilingual settings.

Social Cognition Deficits Are Pervasive across Both Classical and Overlap Frontotemporal Dementia Syndromes.

OBJECTIVES: Frontotemporal dementia (FTD) syndromes are a complex group of disorders characterised by profound changes in behaviour and cognition. Many of the observed behavioural abnormalities are now recognised to be due to impaired social cognition. While deficits in emotion recognition and empathy are well-recognised in behavioural-variant (Bv)FTD, limited information exists about the nature of social cognitive impairment in the language variant primary progressive aphasia (PPA) that includes progressive non-fluent aphasia (PNFA) and semantic dementia (SD), and in the motor variants FTD amyotrophic lateral sclerosis (FTD-ALS) and FTD progressive supranuclear palsy (FTD-PSP). This prospective study sought to explore the nature and profile of social cognition deficits across the spectrum of FTD. METHODS: Sixty patients on the FTD spectrum, i.e., classical (16 with BvFTD and 20 with PPA) and overlap FTD syndromes (13 with FTD-ALS and 11 with FTD-PSP) were evaluated by means of the social cognition tasks, the Interpersonal Reactivity Index (IRI) for empathy, and pictures of facial affect (POFA) for emotion recognition. General cognition and behaviour were also assessed. RESULTS: A significant impairment in emotion recognition and empathy was detected in both the classical and overlap FTD syndromes. The recognition of positive emotions was relatively preserved compared to that of negative emotions. Among the FTD subtypes, maximal impairment of empathy was demonstrated in FTD-PSP. CONCLUSION: Social cognition impairment is pervasive across the spectrum of FTD disorders, and tests of emotion recognition and empathy are clinically useful to identify the nature of behavioural problems in both classical and overlap FTD. Our findings also have implications for understanding the neural basis of social cognition in FTD.

Standardising Dementia Diagnosis Across Linguistic and Educational Diversity: Study Design of the Indian Council of Medical Research-Neurocognitive Tool Box (ICMR-NCTB).

OBJECTIVES: While the burden of dementia is increasing in low- and middle-income countries, there is a low rate of diagnosis and paucity of research in these regions. A major challenge to study dementia is the limited availability of standardised diagnostic tools for use in populations with linguistic and educational diversity. The objectives of the study were to develop a standardised and comprehensive neurocognitive test battery to diagnose dementia and mild cognitive impairment (MCI) due to varied etiologies, across different languages and educational levels in India, to facilitate research efforts in diverse settings. METHODS: A multidisciplinary expert group formed by Indian Council of Medical Research (ICMR) collaborated towards adapting and validating a neurocognitive test battery, that is, the ICMR Neurocognitive Tool Box (ICMR-NCTB) in five Indian languages (Hindi, Bengali, Telugu, Kannada, and Malayalam), for illiterates and literates, to standardise diagnosis of dementia and MCI in India. RESULTS: Following a review of existing international and national efforts at standardising dementia diagnosis, the ICMR-NCTB was developed and adapted to the Indian setting of sociolinguistic diversity. The battery consisted of tests of cognition, behaviour, and functional activities. A uniform protocol for diagnosis of normal cognition, MCI, and dementia due to neurodegenerative diseases and stroke was followed in six centres. A systematic plan for validating the ICMR-NCTB and establishing cut-off values in a diverse multicentric cohort was developed. CONCLUSIONS: A key outcome was the development of a comprehensive diagnostic tool for diagnosis of dementia and MCI due to varied etiologies, in the diverse socio-demographic setting of India.