Many people living with dementia never receive an accurate diagnosis, in part because Alzheimer’s disease, Parkinson’s disease and related conditions are notoriously difficult to tell apart and often occur together. Now, a new tool based on artificial intelligence and a simple blood draw may provide clarity.

The tool can separate these diseases from each other and from typical cognitive changes related to aging with more than 90% accuracy and can detect when a patient has more than one disease process occurring simultaneously—a common but clinically difficult situation that can complicate treatment.