Provided are napthoquinone-type compounds which can be used to modulate the aggregation of protein (e.g. tau) associated with neurodegenerative disease (e.g. Alzheimer's disease). Structure-function characteristics for oxidised and reduced napthoquinone-type compounds, such as menadione-related compounds, are disclosed. The invention further provides methods of treatment or prophylaxis of neurodegenerative diseases and/or clinical dementias based on the compounds.