Investigating Neurocognitive Disorders Epidemiology

The INDE study is a prospective cohort aimed at investigating the natural history and epidemiology of neurocognitive disorders in Thailand. Its primary objective is to develop a predictive model that combines biomarkers (eg. plasma phosphorylated tau) and cognitive performance to accurately predict cognitive decline. Additional objectives include cross-sectional evaluation of various biomarkers for diagnosing disease pathologies, identifying correlations between biomarkers and clinical outcomes, understanding the impact of receiving a biological diagnosis, describing the epidemiology of neurocognitive disorders including risk factors and social determinants of health (SDH), exploring the socioeconomic consequences of these disorders, and establishing a biorepository for future research. The study invites both healthy volunteers and patients referred from memory clinics to participate in a 4-hour visit during which various research procedures are conducted: collection of biospecimens (blood, saliva, sweat), structured interviews covering symptoms, comorbidities, risk factors, SDH, and quality of life, as well as a comprehensive cognitive examination. Participants are scheduled for annual or biennial follow-up visits based on their cognitive status. For those consenting to specific disclosures, investigators provide some biomarker test results and offer post-test counseling based on available research literature. Depending on current funding, a subset of participants meeting additional criteria may also undergo evaluation using appropriate neuroimaging or cerebrospinal fluid (CSF) biomarkers.

• Cognitively Healthy Individuals

Inclusion criteria

• Demonstrate normal cognitive function within the expected range on objective cognitive tests.
• Proficient in speaking and understanding Thai without the need for a translator to participate.

Exclusion criteria

• Significant neurological or uncontrolled psychiatric illness.
• Significant unstable systemic condition or end-stage organ failure that affects study participation.
• Mild Cognitive Impairment

Inclusion criteria

• Display impaired/abnormal performance on objective cognitive tests.
• Does not meet criteria for dementia per NIA-AA (or major neurocognitive disorder per DSM-5).
• Proficient in speaking and understanding Thai without the need for a translator to participate.

Exclusion criteria

• Significant neurological or uncontrolled psychiatric illness.
• Significant unstable systemic condition or end-stage organ failure that affects study participation.
• Late Onset Dementia

Inclusion criteria

• Display impaired/abnormal performance on objective cognitive tests.
• Meets criteria for dementia per NIA-AA (or major neurocognitive disorder per DSM-5), including dementia due to Alzheimer's disease or other causes.
• Begins to experience symptoms, identified by the physician as a part of dementia continuum, occurring after the age of 65.
• Proficient in speaking and understanding Thai without the need for a translator to participate.

Exclusion criteria

• Significant neurological or uncontrolled psychiatric illness.
• Significant unstable systemic condition or end-stage organ failure that affects study participation.
• Early Onset Dementia

Inclusion criteria

• Display impaired/abnormal performance on objective cognitive tests.
• Meets criteria for dementia per NIA-AA (or major neurocognitive disorder per DSM-5), including dementia due to Alzheimer's disease or other causes.
• Begins to experience symptoms, identified by the physician as a part of dementia continuum, occurring before the age of 65.
• Proficient in speaking and understanding Thai without the need for a translator to participate.

Exclusion criteria

• Significant neurological or uncontrolled psychiatric illness.
• Significant unstable systemic condition or end-stage organ failure that affects study participation.