The invention provides compounds for the treatment of Alzheimer's disease, methods for the use of such compounds, assays for the identification of such compounds, and methods for diagnosis of Alzheimer's disease and diagnostic kits. Methods of marketing compounds are also disclosed. In one aspect, the disclosure provides a compound for the diagnosis or treatment of Alzheimer's disease wherein the compound is a modulator that inhibits the disruption by amyloid β of a complex comprising synaptophysin and/or synaptobrevin. In another aspect, the disclosure provides a pharmaceutical composition comprising the compounds disclosed herein in an amount sufficient to treat Alzheimer's disease in a subject. In another aspect, the disclosure provides a diagnostic composition comprising the compound disclosed herein.