Cognitive Decline
A gradual deterioration in memory, attention, processing speed, and executive function. Cognitive decline may be age-related or indicative of neurodegenerative disease. No research peptide has received regulatory approval for preventing cognitive decline, though several are investigated in preclinical studies.
Technical Context
Cognitive decline spectrum: subjective cognitive decline (SCD — self-perceived decline without objective impairment on testing, may represent earliest detectable stage), mild cognitive impairment (MCI — objective cognitive impairment beyond age expectations but preserved daily functioning; amnestic MCI converts to Alzheimer's at approximately 10-15% per year), and dementia (cognitive impairment affecting daily functioning — Alzheimer's disease accounts for 60-70% of cases). Biomarkers: amyloid PET and CSF Aβ42 (amyloid pathology), tau PET and CSF phospho-tau (tau pathology), FDG-PET (neuronal metabolism), MRI volumetry (hippocampal atrophy). Modifiable risk factors (Lancet Commission 2020): 12 risk factors account for approximately 40% of dementia risk — education, hearing loss, hypertension, obesity, smoking, depression, physical inactivity, diabetes, excessive alcohol, traumatic brain injury, air pollution, and social isolation. No peptide drug is currently approved for preventing cognitive decline, though research continues.