NCT03663387

Who might be able to join this trial:

• You are between 20 and 100 years old (younger people are not included because the condition being studied is very rare in younger age groups)
• You speak English as your first language, or you are able to communicate well in English
• You may have normal memory and thinking skills, or you may already have some memory or thinking difficulties
• You are in good general health and are able to take part in brain scans and a spinal fluid collection procedure, as decided by the study doctor

Who may not be able to join:

• You have high blood pressure or a metabolic condition (such as diabetes) that is not well controlled
• You have a brain or nervous system condition such as Parkinson's disease, Lewy body disease, or frontotemporal dementia
• You have had severe, long-lasting depression throughout your life, or you score 20 or higher on a standard depression questionnaire at the start of the study
• You have had a long-term serious mental health condition (as defined by a specific medical classification system) (confirm with trial site)
• You have an intellectual disability
• You have a history of substance abuse
• You are currently taking medications that could interfere with memory testing or brain scans, including certain antidepressants, MAO inhibitors, regular strong painkillers (more than twice a week), or antipsychotic medications
• You have a medical device implanted in your body that is not safe to use with MRI scanners
• You have already been exposed to significant levels of radiation that meet or exceed yearly safety limits for radiation workers
• You have very advanced heart failure (stage D)
• You have advanced kidney disease (stage 4 or higher)
• You have a brain tumour, or a cancer elsewhere in your body whose treatment (such as chemotherapy or radiation) is likely to affect your brain
• You have had a significant stroke (though small, silent strokes or mini-strokes do not automatically exclude you — confirm with trial site)
• You have had a serious head injury
• You have a condition where fluid builds up in the brain (hydrocephalus)
• You are unwilling or unable to cooperate with the study team
• You are currently taking long-term blood-thinning medication
• You are taking part in another research study that involves additional radiation exposure, an experimental drug or treatment, or that does not allow you to join other studies — though participation in other observational (non-treatment) studies may be allowed

Important: Always verify eligibility with the trial site directly before applying.