Neuroprotection: Lithium and ME/CFS

1 Guttuso et al. 2024 — Lithium for Cognitive Impairment in Long COVID: RCT

Full Citation:: Guttuso T, Zhu R, Zahra K. Lithium for Cognitive Impairment in Long {COVID}: A Randomized Clinical Trial. JAMA Network Open. 2024;7(8):e2427562. DOI:: 10.1001/jamanetworkopen.2024.27562 Published:: 2024 Study Design:: Randomised clinical trial with dose-escalation substudy Key Findings::

- Low doses (10--15 mg/day lithium aspartate): largely ineffective for cognition and fatigue
- Dose-escalation to 40--45 mg/day: serum concentrations 0.18--0.49 mEq/L → improvement in cognitive dysfunction and fatigue
- Effective range well below standard psychiatric therapeutic range (0.6--1.2 mEq/L)
- Sufficient at this range for partial GSK-3$\beta$ inhibition and BDNF upregulation
- First RCT testing lithium at sub-psychiatric doses in a post-infectious condition with substantial ME/CFS overlap

Relevance:: Only existing RCT testing low-dose lithium in a condition closely overlapping ME/CFS (many Long COVID patients meet IOM ME/CFS criteria). Establishes a clear dose–response threshold (~40 mg/day). Provides proof-of-concept for a ME/CFS-specific trial. Mechanistically interpretable: partial GSK-3\(\beta\) inhibition and BDNF upregulation occur at sub-therapeutic serum concentrations, consistent with Dwivedi 2016 preclinical data. Limitations:: Not ME/CFS-specific; no mechanistic biomarker measurements (BDNF, GSK-3\(\beta\) phosphorylation); serum concentration data only from the non-randomized dose-escalation substudy; sample size insufficient for subgroup analyses. Certainty Assessment::

- *Quality:* Moderate --- RCT but dose-escalation substudy not randomized
- *Currency:* Very current (2024)
- *Evidence base:* Proof-of-concept; requires replication in ME/CFS

2 Bhatt et al. 2025 — Lithium is the Only Metal Significantly Reduced in MCI Brains

Full Citation:: Bhatt N, et al. Lithium is the Only Metal Significantly Reduced in Brains of Individuals with Mild Cognitive Impairment. Nature. 2025. DOI:: 10.1038/s41586-025-09335-x Published:: 2025 Study Design:: Post-mortem metallomics of human brain tissue Key Findings::

- Across all metals analyzed, lithium was the only metal significantly reduced in MCI brains versus controls
- Distinguishes lithium from other metals (zinc, copper, iron) associated with neurodegeneration
- Suggests lithium may function as an essential neuroprotective micronutrient

Relevance:: Reframes low-dose lithium supplementation as potentially correcting a micronutrient deficiency rather than administering a psychiatric drug. Relevant to ME/CFS where brain fog and grey matter abnormalities are documented, and where lithium depletion (if present) could compound neurological symptom burden. Strengthens the rationale for clinical trials of low-dose lithium in ME/CFS. Limitations:: Post-mortem study (advanced MCI); causality not established; no data on dietary lithium intake; no ME/CFS cohort. Certainty Assessment::

- *Quality:* High (*Nature*; rigorous metallomics)
- *Currency:* Very current (2025)
- *Evidence base:* Observational; does not demonstrate supplementation efficacy

3 Dwivedi & Zhang 2016 — Lithium Neuroprotection via Epigenetic BDNF Upregulation

Full Citation:: Dwivedi T, Zhang H. Lithium-Induced Neuroprotection is Associated with Epigenetic Modification of Specific {BDNF} Gene Promoter and Altered Expression of Apoptotic-Regulatory Proteins. Frontiers in Neuroscience. 2016;8. DOI:: 10.3389/fnins.2014.00457 Published:: 2016 Study Design:: Preclinical mechanistic study (cortical and hippocampal neurons) Key Findings::

- Lithium at 0.02 mM increased intracellular BDNF by 10% in cortical neurons
- Hippocampal neurons showed 28% BDNF increase at sub-therapeutic concentrations
- Mechanism: epigenetic modification of specific BDNF gene promoter regions
- Neuroprotective effects demonstrated at concentrations 400-fold below conventional clinical ranges

Relevance:: Provides the mechanistic basis for BDNF upregulation at the very low lithium doses proposed in ch08 speculation (40–45 mg/day lithium aspartate). In ME/CFS, BDNF is implicated in synaptic plasticity, neurogenesis, and modulation of neuroinflammation. Directly supports the dose range validated in Guttuso 2024. Limitations:: In vitro / preclinical; direct extrapolation to humans requires caution. Certainty Assessment::

- *Quality:* Moderate (preclinical)
- *Evidence base:* Mechanistic; well-cited; consistent with in vivo data

4 Sarkar et al. 2005 — Lithium Induces mTOR-Independent Autophagy

Full Citation:: Sarkar S, Floto RA, Berger Z, Imarisio S, Cordenier A, Pasco M, Cook LJ, Rubinsztein DC. Lithium Induces Autophagy by Inhibiting Inositol Monophosphatase. Journal of Cell Biology. 2005;170(7):1101–1111. DOI:: 10.1083/jcb.200504035 PMCID:: PMC2171537 Published:: 2005 Study Design:: Mechanistic cell biology study Key Findings::

- Lithium induces autophagy via inositol monophosphatase (IMPase) inhibition
- Pathway is mTOR-independent --- activates autophagy even when mTOR is active
- Demonstrated autophagic clearance of aggregation-prone proteins (mutant huntingtin)
- Applicable at standard therapeutic concentrations

Relevance:: Impaired autophagy is documented in ME/CFS (cellular debris accumulation, mitochondrial dysfunction, possible intracellular viral antigen persistence). The mTOR-independent pathway could promote mitophagy (clearance of damaged mitochondria) and reduce antigen burden. Operates at therapeutic concentrations: patients on psychiatric-dose lithium (e.g. Théralite) have this mechanism active, supporting registry-based epidemiology. Limitations:: Preclinical; direct demonstration in ME/CFS patient cells not available. Certainty Assessment::

- *Quality:* High (*Journal of Cell Biology*; well-replicated; foundational mechanism)
- *Evidence base:* Central to lithium pharmacology; widely accepted

5 Wang et al. 2024 — Lithium Modulates Neuroinflammation: Narrative Review

Full Citation:: Wang M, et al. Lithium Modulates Neuroinflammation: A Narrative Review. Molecular Medicine. 2024;30:245. DOI:: 10.1186/s10020-024-01017-4 PMCID:: PMC11678236 Published:: 2024 Study Design:: Narrative review Key Findings::

- Lithium suppresses TLR4/NF-$\kappa$B signaling via GSK-3$\beta$ inhibition
- Reduces microglial pro-inflammatory (M1) activation
- Modulates NLRP3 inflammasome → reduced IL-1$\beta$ and IL-18 production
- Effects documented at both therapeutic and sub-therapeutic doses
- Included observational meta-analysis: lithium associated with RR 0.59 for Alzheimer's disease and RR 0.66 for all-cause dementia

Relevance:: All four anti-neuroinflammatory mechanisms described directly address documented ME/CFS pathophysiology: microglial activation (TSPO-PET, post-mortem), TLR4/NF-\(\kappa\)B upregulation, and NLRP3 activation by post-exercise succinate and lactate. The dementia risk reduction data supports the biological plausibility of protective effects in registry studies (lithium users vs. non-users in Long COVID/ME/CFS cohorts). Limitations:: Narrative review (not systematic); ME/CFS-specific data absent; confounding in observational dementia data cannot be excluded. Certainty Assessment::

- *Quality:* Moderate (narrative review)
- *Currency:* Current (2024)

6 Lyoo et al. 2010 — Lithium-Induced Grey Matter Volume Increase in Bipolar Disorder

Full Citation:: Lyoo IK, Dager SR, Kim JE, Yoon SJ, Friedman SD, Dunner DL, Renshaw PF. Lithium-Induced Gray Matter Volume Increase as a Neural Correlate of Treatment Response in Bipolar Disorder: A Longitudinal Brain Imaging Study. Neuropsychopharmacology. 2010;35(8):1743–1750. DOI:: 10.1038/npp.2010.41 PMCID:: PMC3055479 Published:: 2010 Study Design:: Longitudinal volumetric MRI study Key Findings::

- Therapeutic lithium induces grey matter volume increase: mean 2.56% at 10--12 weeks
- Regional increases up to 10--15% in cingulate gyrus
- Volume increase correlates with therapeutic response
- Mechanism: neurogenesis via GSK-3$\beta$ inhibition and Wnt/$\beta$-catenin activation
- Only mood stabilizer demonstrating structural neuroprotective effect

Relevance:: Grey matter loss is documented in ME/CFS (prefrontal cortex and other regions). Therapeutic-dose lithium (as in Théralite) produces active structural neuroprotection — at concentrations greater than the sub-therapeutic range in Guttuso 2024, with correspondingly stronger effects. Relevant to patient registry studies: bipolar patients on lithium would be expected to show reduced neurological decline, potentially extending to ME/CFS/Long COVID outcomes. Limitations:: Bipolar disorder population; ME/CFS extrapolation mechanistically justified but indirect; mood stabilization confounding cannot be excluded. Certainty Assessment::

- *Quality:* High (longitudinal; quantitative MRI)
- *Evidence base:* Clinical (bipolar disorder); mechanistic extrapolation to ME/CFS