Inclusion Criteria:
For All Participants (HV and AD groups):
- Age between 50 and 85 years
- Ability to understand and sign informed consent
- Availability for the full duration of the study (24 months)
- Fasting capability for morning sample collection (between 8:30-12:00)
- Willingness to provide blood and urine samples for biomarker analysis and biobank storage
Additional Criteria for Healthy Volunteers (HV):
- No history or current diagnosis of neurodegenerative disease
- Normal cognitive function confirmed by neuropsychological testing (e.g., MMSE score within normal range)
- No significant abnormalities on brain imaging (CT or MRI if performed)
- No use of medications affecting cognitive function
Additional Criteria for Alzheimer's Disease Patients (AD):
- Clinical diagnosis of probable Alzheimer's disease based on standardized criteria
- Cognitive impairment confirmed by neuropsychological testing (e.g., MMSE score below threshold)
- Supporting evidence from brain imaging (CT or MRI) and/or cerebrospinal fluid biomarkers (if available)
- Stable medical condition allowing participation in study procedures
Exclusion Criteria:
For All Participants:
- History of major psychiatric disorders (e.g., schizophrenia, bipolar disorder)
- Significant neurological conditions other than Alzheimer's disease (e.g., Parkinson's disease, stroke)
- Active malignancy or history of cancer within the past 5 years (except localized skin cancer)
- Severe renal, hepatic, or cardiovascular disease
- Current participation in another interventional clinical trial
- Known blood disorders or conditions affecting red blood cell morphology or function
- Recent blood transfusion (within 3 months)
- Substance abuse or alcohol dependence
- Inability to comply with study procedures
Additional Exclusion for Healthy Volunteers:
- Any cognitive complaints or subjective memory loss
- First-degree family history of Alzheimer's disease (optional, depending on stratification strategy)
- Use of psychoactive medications
Additional Exclusion for Alzheimer's Disease Patients:
- Diagnosis of mixed or atypical dementia
- Rapidly progressive cognitive decline suggestive of other pathology
- Contraindications to lumbar puncture (if CSF sampling is planned)