The described invention relates to methods for treating, preventing, or diagnosing the pathology of progressive cognitive disorders resulting from accumulation of an amyloid peptide, in particular, Alzheimers disease, Downs syndrome and cerebral amyloid angiopathy, in mammalian subjects using a composition comprising therapeutically effective amount of a leptin, leptin mimic, leptin derivative, leptin agonist, or AMP-dependent protein kinase activator, alone, or in combination with, one or more lipolytic/antilipogenic compounds. It further relates to methods for improving cognitive function using a composition comprising a therapeutically effective amount of leptin, a leptin mimic, a leptin derivative, an AMP-dependent protein kinase activator, a leptin agonist, a leptin blocker, a mimic of a leptin blocker, a leptin antagonist, an AMP-dependent protein kinase inhibitor or a pharmaceutically acceptable salt thereof.
