Mental health disorders affect nearly one in eight people worldwide, representing a significant global public health concern. The burden is particularly high in low and middle income countries, where challenges such as limited healthcare infrastructure, inadequate workforce, cultural stigma, and low budget allocation severely constrain access to mental health care. Mental illnesses contribute more to years lived with disability than many major non communicable diseases, including heart disease and cancer. In India, the National Mental Health Survey reported a lifetime prevalence of 13.7 percent for mental health conditions estimating that nearly 150 million people require active mental health support. Despite this, the treatment gap remains between 70 and 92 percent across different disorders and population groups, illustrating the iceberg phenomenon where only a small portion of affected individuals receive diagnosis and treatment while the majority remain undetected and untreated. Conventional screening instruments are often time consuming, limited in diagnostic scope, and not adequately adapted to India’s cultural and linguistic diversity. These tools frequently miss subclinical symptoms and comorbid psychiatric conditions. The MASTISHQ or Mental health Assessment Tool for Integrated Screening and Health evaluation based Questionnaire module CoreScan Surface aims to address these limitations by providing a digital, scalable, and culturally sensitive approach to mental health screening. The tool comprises 217 items covering 25 common psychiatric conditions, including mood, anxiety, psychotic, personality, eating, and substance use disorders, along with neurodegenerative conditions such as dementia and Parkinson disease. It also assesses psychosocial domains including relationship difficulties, predisposition to mental illness, and occupational stress. This cross sectional observational study will be conducted in the Department of Psychiatry at the Himalayan Institute of Medical Sciences, Dehradun, following approval from the Institutional Ethics Committee. Participants with or without mental illness who are able to understand English and provide informed consent will be recruited. Those with sensory impairments that may interfere with the assessment will be excluded. Recruitment will be purposive, focusing on hospital based participants, and each assessment is expected to take approximately 45 to 60 minutes. Screening using the MASTISHQ CoreScan Surface will be administered by trained psychiatrists, and results will be compared with formal clinical diagnoses established using standard diagnostic criteria. To ensure objectivity, diagnostic verification will be carried out by independent psychiatrists who are not part of the tool development team. A minimum of 30 participants will be enrolled, and data will be analyzed using standard statistical methods. Diagnostic performance will be assessed through sensitivity, specificity, positive predictive value, and negative predictive value. Internal consistency will be measured using Cronbach alpha, inter rater reliability through Cohen kappa, and content validity by experienced psychiatrists evaluating the tool’s relevance, comprehensiveness, and cultural appropriateness. The study seeks to validate the MASTISHQ CoreScan Surface as a reliable, efficient, and culturally appropriate digital screening instrument that can facilitate early identification and management of mental health disorders within the Indian population.