Psychiatry, as a discipline, has its origin in Western/Caucasian culture historically. The majority of the screening tools and rating scales used for psychiatric disorders have been developed and validated in the western population of high-income countries (HICs). The conventional practice is to translate the already established screening tools and rating scales in the language of the target population in other regions of the world and carry out validation studies in that population. However, this process has not been consistently applied for several screening/diagnostic tools and rating scales, especially in South Asia.

Verbatim translations of screening tools and rating scales are not appropriate as they fail to capture the cultural nuances influencing different symptom profiles and their linguistic expression across different societies/cultures. This is, especially, true for low and middle-income countries (LMICs) of South Asia wherein composite cultural context, ethnic, and linguistic diversity influence the experience and expression of distress, symptoms, and disability for psychiatric disorders. Verbatim translations fail to capture cultural idioms and result in an inadequate assessment of construct under evaluation due to issues pertaining to cross-cultural validity (most common) and reliability (less common).

In addition, educational status of the target population is rarely taken into account while developing and validating translated tools, especially for self-rated scales and questionnaires. During the conduct of validation studies, there is no client education-specific sub-analysis for the subset of the target population with limited formal education. The content validity metrics of translated tools for clients with limited educational attainment are neither established and nor commented upon in reviews. This is a significant gap in research, especially for epidemiological studies.

The current review by Fotheringham et al. (2021) aims to systematically evaluate these issues by reviewing available current literature on the topic. The methodology adopted by the authors is robust and justifies the aim of this comprehensive review.

The studies were selected after a systematic literature search was performed in MEDLINE, Embase, PsycInfo, Scopus, and Web of Science using a two-stage screening process following PRISMA guidelines. A total of 176 studies were finally included for review. The majority of included studies were from India (75%, n = 132), followed by Pakistan (13.1%, n = 23) and Nepal (5.7%, n = 10). Sri Lanka had nine studies and Bangladesh had two studies while no studies from Afghanistan, Bhutan, and Maldives could be found. The preponderance of studies from India indicates that large geographic regions in South Asia are underserved. This could reflect the treatment gap, differences in the level of mental health service delivery, and research being conducted in different countries of South Asia.

Of the 176 included studies, there were 160 epidemiological studies and only 16 validation studies whose quality was assessed using a standardized tool, namely Quality Assessment of Diagnostic Accuracy Studies – Version 2 (QUADAS-2) (Whiting et al., Reference Whiting2011). Four studies, that did not examine the performance of tools as diagnostic tests but explored other measures of validity, were not assessed for quality assessment (Ahmad et al., Reference Ahmad, Hussain, Shah and Akhtar2017; Chokkanathan and Mohanty, Reference Chokkanathan and Mohanty2013; Ganguli et al., Reference Ganguli, Dube, Johnston, Pandav, Chandra and Dodge1999).

Only studies that used a tool, questionnaire, or instrument to identify or screen for a clinically defined common mental disorder were included in the review while studies on rating scales were excluded. The majority of the studies focussed on screening tools (n = 120) with a preponderance of tools for depression (82%). Only 15 tools for the assessment of common mental disorders in South Asia were identified. Almost half of the studies (n = 95) used 15 and 30 items Geriatric Depression Scale (GDS-15, GDS 30). The other screening tools studied were the Center for Epidemiological Studies – Depression (CES-D), European Union – Depression (EURO-D), and Patient Health Questionnaire (PHQ) (Banerjee et al., Reference Banerjee, Kumar, Kulhara and Gupta2008; Barua et al., Reference Barua, Ghosh, Kar and Basilio2010; Biswas et al., Reference Biswas2009; Guerra et al., Reference Guerra2016; Khattri and Nepal, Reference Khattri and Nepal2006; Kulathunga et al., Reference Kulathunga, Umayal, Somaratne, Srikanth, Kathriarachchi and De Silva2010; Prince et al., Reference Prince2004; Sarkar et al., Reference Sarkar, Kattimani, Roy, Premarajan and Sarkar2015).

There was one novel indigenous tool that aimed to assess death anxiety in urban community residents in Jaipur, Rajasthan, India, but the study was not designed to objectively evaluate validity which has been elaborated adequately in the paper (Madnawat and Kachhawa, Reference Madnawat and Kachhawa2007). The paucity of novel tools for the assessment of common mental disorders in South Asia was clearly emphasized in the review by Fotheringham et al.

A limited number of studies (n = 28) focussed on diagnostic tools with Geriatric Mental State (GMS) (n = 15) and Composite International Diagnostic Interview (CIDI) (n = 13) being the most frequently studied.

On exploration, it was found that only about half of the studies used tools that were culturally validated in accordance with WHO guidelines or with proven cross-cultural applicability (e.g. GMS and CIDI [Haro et al., Reference Haro2006; Prince et al., Reference Prince2004]), leaving valid doubts about the validity and reliability of data captured in epidemiological studies not using culturally validated tools. Two recent reviews (Pilania et al., Reference Pilania2019; Thapa et al., Reference Thapa, Visentin, Kornhaber and Cleary2018) have emphasized that reliance on translated scales from HICs, with insufficient cultural and linguistic validation to make diagnosis have possibly resulted in increased prevalence rates of mental disorders in epidemiological studies using such tools in South Asia.

The authors have also discussed in detail the scientific issues relating to adapting HIC tools for LMICs and its public health policy implication for South Asia, comparing with credible research done in LMICs like Zimbabwe and Palestine and UMIC like China.

Fifteen reviews, including seven meta-analyses were also included in the study, majority of which focussed either on depression or elderly mental health (n = 6 each). There was a paucity of reviews on other common mental disorders like anxiety disorder, obsessive-compulsive disorders, bipolar affective disorder, and psychotic disorders. These reviews were not specifically related to the evaluation of specific screening, diagnostic or rating scales, or tools.

The review by Fotheringham et al. (2021) while comprehensive also has some limitations. While the authors acknowledge that “South Asian countries are often considered together in large meta-analyses”, no meta-analysis was performed during the review. If meta-analysis could not be conducted due to lack of harmonized protocols, it should have been stated explicitly by the authors. This would sensitize researchers to, henceforth, create harmonized protocols so that multicentric, multicountry datasets are amenable for meta-analysis in the future.

Language is an important component of culture. Language carries the cultural nuances, metaphors, contexts, and culturally sanctioned concepts of well-being, psychological issues, idioms of distress, and psychiatric symptomology expressed in a way understandable to native speakers. South Asia is a linguistically diverse region. India itself has 122 major languages and 1599 other languages including dialects. Of these, there are more than a million native speakers for 30 major languages while there are more than 10,000 native speakers for another 122 languages (Office of The Registrar General of India, 2011). Other countries in South Asia also have multiple languages, which are spoken by a substantial number of people. However, the authors have not even mentioned the names of the languages for the translated scales, which is a major omission. The review leaves the reader without any idea about the languages in which translated tools for common mental disorders are available or not available, thereby necessitating accessing individual papers to understand the availability of vernacular versions.

Further, the authors have not explicitly commented whether studies published in regional languages other than English were available, but were not included in the paper. In addition, the quality assessment was only limited to validation studies assessed against a gold standard. Quality assessment of the remaining studies could have been performed using a comparable standardized checklist.

To conclude, there is a fundamental gap for culturally appropriate composite assessment of psychiatric disorders in South Asia given the lack of reference standards. There is a considerable lacuna in research related to the validation of various scales and tools, originally developed in HICs, in South Asia. In addition, there are only a limited number of indigenously developed scales for screening/diagnosing/rating common mental disorders. The majority of validation studies are on scales for assessment of depression with a dearth of studies on other common mental disorders. Most of the validation studies have not accounted for disparities in educational impairment, cultural diversity, and linguistic differences while assessing translated tools resulting in valid doubts on the results of research studies utilizing such scales. Further, the preponderance of studies from India indicates that large populations in South Asia and even different linguistic groups within India remain underserved.

Further research is required for appropriate validation of existing tools and the creation of novel indigenous tools taking into account cultural and linguistic diversity as well as educational disparity influencing the experience and expression of common mental disorders in the South Asian population.