The goal of this clinical trial is to evalute the efficacy of ALZGUARD, a smartphone-based digital therapeutic(DTx), in comparison to diagnosis by medical doctors, as weel as to assess the safety of the application.

The study will be conducted across multiple sites, enrolling participants aged 55 to 85 years olds.

The primary objective of the study is to compare the diagnositic accuracy of ALZGAURD against traditional diagnostic evaluactions conducted by medical professionals. The primary endpoint for efficacy will be the Area Under the Curve(AUC), which will measure the diagnostic performance of the application. This statistical metric will help determine how well ALZGUARD can identify dementia compared to standard diagnostic methods.

Inclusion Criteria:

• Participants must be between 55 and 85 years old (both men and women).
• Participants must be able to understand and voluntarily agree to the purpose, content, and procedures of the clinical trial.

Exclusion Criteria:

• Participants with no literacy or illiteracy.
• Participants with an intellectual disability.
• Participants with presenting active psychiatric symptoms.
• Participants who have difficulty ALZGUARD application
• Participants who are unable to use a smartphone, unless they can use it with assistant.
• Participants with a history of suicidal ideation or suicidal complusion in the last 6 months.
• Other conditions as deemed inappropriate for study participant by the Principal Investigator(PI).

In this study, there will be two data analysts involved. Analyst 1 will be responsible for analyzing the results generated by the ALZGUARD application, which are based on the ALZGUARD AI model. This analyst will assess whether each subject has dementia and the likelihood or probability of the diagnosis. Analyst 1 will be blinded to any clinical assessments or dianoses made by the neurologists.