Low-Dose Lithium for ALS
Also known as: Lithium orotate, Lithium aspartate, Microdose lithium
Low-dose lithium modulates GSK3β and promotes autophagy — two mechanisms highly relevant to ALS motor neuron survival.
Mechanism of Action
Lithium inhibits GSK3β (reducing tau/TDP-43 phosphorylation), induces autophagy through mTOR-independent IP3 pathway, enhances BDNF and GDNF expression, and inhibits excitotoxicity through glutamate transporter upregulation. Low doses achieve neuroprotection without mood-stabilizing levels.
General mechanism: GSK3β inhibitor. Autophagy inducer (IP3 pathway). BDNF/GDNF enhancer. Neuroprotective at microdoses.
Current Evidence
Initial Fornai et al. (2008) study showed ALS benefit, but subsequent trials (LiCALS, LITRA) were negative at standard lithium levels. Microdose lithium (<300μg) may provide neuroprotection without toxicity — studies revisiting this approach.
Clinical Status: Standard-dose trials negative. Microdose lithium for neuroprotection being re-evaluated.
Safety Profile
Microdose (<1mg): very safe. Standard dose (600-1200mg): renal, thyroid toxicity requiring monitoring. Narrow therapeutic index at psychiatric doses.
Key Research Questions
- Does microdose lithium achieve GSK3β inhibition without renal/thyroid toxicity?
- Can lithium's autophagy induction clear TDP-43 aggregates in ALS?