Disclosed and claimed herein are compositions comprising ADDL receptors, related compositions, and related methods. ADDL receptors are typically, but perhaps not exclusively, localized at the post-synaptic density (PSD) of neuronal cells. Related compositions include, but are not limited to, compounds that affect, positively or negatively, ADDL binding to neuronal cells, either via one or more receptors localized at the post-synaptic density (PSD) or otherwise. Related methods include, but are not limited to, procedures to screen for compounds that affect, either positively or negatively, ADDL binding to neuronal cells, either via one or more receptors localized at the post-synaptic density (PSD) or otherwise. Other related methods include, but are not limited to, prevention and treatment of ADDL-related diseases, such as Alzheimer’s disease, mild cognitive impairment, Down’s syndrome, and the like, using compositions that inhibit, block, or otherwise interfere with ADDL binding to one or more receptors localized at the post-synaptic density of neuronal cells.