Neurodegeneration announces itself early, in anxiety, blood, and spinal fluid

Anxiety as a circuit, not a symptom

Anxiety in older adults is often treated as a mood issue adjacent to dementia. A preprint argues it is part of the disease process itself. The researchers find that anxiety in cognitively unimpaired older adults is independently associated with Alzheimer's-related atrophy networks. The anxiety-linked network also shows high spatial convergence with a causal anxiety network derived from lesion and neuromodulation data, which strengthens the case that the link is anatomical rather than coincidental. m:…0350

The clinical weight comes from follow-up: greater atrophy in the identified anxiety network predicts cognitive decline over 4.6 years. If that holds, anxiety screening in cognitively healthy older adults could become a route into earlier monitoring, not just a mental-health referral. The paper frames the network as a potential non-invasive biomarker, and the longitudinal prediction is what makes that framing plausible. m:…0350

A midlife signal in blood

A second preprint looks even earlier, to blood. The study identifies a circulating plasma proteomic signature that predicts future cognitive decline, incident dementia, and later-life Alzheimer's pathology. The signature is enriched in astrocyte, microglia, and endothelial pathways beyond the APOE region, which matters because it points to mechanisms outside the well-trodden APOE story. The authors describe it as capturing molecular processes associated with future susceptibility that precede conventional biomarkers. m:…9665

The practical promise is risk stratification decades before symptoms: a blood-based window into susceptibility that could shape who gets monitored, and eventually who enters prevention trials. The caveat is the usual one for biobank findings: prediction in a cohort is not yet a test in a clinic, and the signature needs validation in other populations and with standardized assays. m:…9665

What makes the signature scientifically interesting, beyond its predictive value, is where it points. Enrichment in astrocyte, microglia, and endothelial pathways beyond the APOE region suggests that susceptibility involves the brain's support and barrier systems, not only neuronal damage pathways. That broadens the search for early intervention targets: if glial and vascular processes are part of the earliest signal, they may also be part of the earliest opportunity. m:…9665

Splitting ALS by prognosis

The third preprint applies the same early-signal logic to ALS, where prognosis varies widely and trials struggle with heterogeneity. A subset of patients with strong spinal-fluid alpha-synuclein seeding activity shows shorter tracheostomy-free survival, with an adjusted hazard ratio of 2.08. The marker also modifies the association between neurofilament light chain and functional decline, meaning it changes how an established biomarker should be read. m:…4814

Notably, ALS patients show significantly lower odds of this seeding positivity than patients with Alzheimer's dementia, which helps place the marker: it identifies a distinct ALS subgroup rather than a generic neurodegeneration signal. For trial designers, that subgroup is actionable. Stratifying by it could sharpen outcome measurement and prognostic counseling, provided the assay holds up in prospective use. The same logic runs through all three papers: find the subgroup early, and both care and research get sharper, because early detection is the common thread. m:…4814

The three papers also share a practical implication for anyone building early-detection programs. A useful early signal does not have to be a diagnosis, and it does not have to work alone. An anxiety-linked brain network, a blood protein signature, and a spinal-fluid assay each add one layer of stratification, and the value comes from combining layers rather than waiting for a single definitive test. m:…0350 m:…9665 m:…4814