Temporal order is subtype-specific rather than universal

Mechanistic description

The most defensible synthesis is that AD contains at least two trajectory classes: an amyloid-clearance/endosomal class and a trophic-transport/cholinergic-vulnerability class. This is less a single mechanism than a framework that can reconcile heterogeneous human biomarker sequences and guide stratified trials.

Mechanism / pathway

APOE, SORL1, NTRK1, BIN1, PICALM
→
neurodegeneration

Evidence for (7)

Multimodal human biomarkers now support trajectory stratification using amyloid, tau, APOE, basal forebrain, and locus coeruleus measures.

PMID:28894304
Early cholinergic imaging and basal forebrain structural readouts provide a practical axis for testing non-identical prodromal paths.

PMID:37086935
ApoE in Alzheimer's disease: pathophysiology and therapeutic strategies.

PMID:36348357 2022 Mol Neurodegener
Apolipoprotein E and Alzheimer disease: pathobiology and targeting strategies.

PMID:31367008 2019 Nat Rev Neurol
APOE deficiency inhibits amyloid-facilitated (A) tau pathology (T) and neurodegeneration (N), halting progressive ATN pathology in a preclinical model.

PMID:40307424 2025 Mol Psychiatry
Silencing Apoe with divalent-siRNAs improves amyloid burden and activates immune response pathways in Alzheimer's disease.

PMID:38375983 2024 Alzheimers Dement
The probabilistic model of Alzheimer disease: the amyloid hypothesis revised.

PMID:34815562 2022 Nat Rev Neurosci

Evidence against (2)

Subtype formulations can become post hoc and unfalsifiable unless classes are preregistered and replicated across independent cohorts.
Apparent classes may reflect measurement thresholds, staging, or co-pathology rather than true discrete biology.

Evidence matrix

7 supporting 2 contradicting

78% supporting

Supporting

Multimodal human biomarkers now support trajectory stratification using amyloid, tau, APOE, basal forebrain, and locus coeruleus measures. PMID:28894304
Early cholinergic imaging and basal forebrain structural readouts provide a practical axis for testing non-identical prodromal paths. PMID:37086935
ApoE in Alzheimer's disease: pathophysiology and therapeutic strategies. PMID:36348357 · 2022 · Mol Neurodegener
Apolipoprotein E and Alzheimer disease: pathobiology and targeting strategies. PMID:31367008 · 2019 · Nat Rev Neurol
APOE deficiency inhibits amyloid-facilitated (A) tau pathology (T) and neurodegeneration (N), halting progressive ATN pathology in a preclinical model. PMID:40307424 · 2025 · Mol Psychiatry
Silencing Apoe with divalent-siRNAs improves amyloid burden and activates immune response pathways in Alzheimer's disease. PMID:38375983 · 2024 · Alzheimers Dement
The probabilistic model of Alzheimer disease: the amyloid hypothesis revised. PMID:34815562 · 2022 · Nat Rev Neurosci

Contradicting

Subtype formulations can become post hoc and unfalsifiable unless classes are preregistered and replicated across independent cohorts.
Apparent classes may reflect measurement thresholds, staging, or co-pathology rather than true discrete biology.

Cite this hypothesis

Citation

etl-backfill (2026). Temporal order is subtype-specific rather than universal. SciDEX hypothesis. https://prism.scidex.ai/hypotheses/h-26353f7f59

BibTeX

@misc{scidex_hypothesis_h26353f7,
  title        = {Temporal order is subtype-specific rather than universal},
  author       = {etl-backfill},
  year         = {2026},
  howpublished = {SciDEX hypothesis},
  url          = {https://prism.scidex.ai/hypotheses/h-26353f7f59},
  note         = {SciDEX artifact hypothesis:h-26353f7f59}
}