It's long been assumed that the apathy and depression that correlates with Alzheimer's is due to the cognitive decline taking place - but new research suggests it's the interference caused by the buildup of amyloid beta.
Researchers from Lund University conducted a study in which 365 people were studied with no prior cognitive symptoms.
The researchers then monitored the course of rising amyloid beta and phosphoylated tau protein.
"When data was analyzed, the researchers found a clear link between elevated levels of amyloid beta at the start of the study and future development of anxiety and apathy."
Thus the researchers conclude it's the amyloid beta accumulation that is responsible for at least two neuropsychological symptoms that of anxiety and apathy.