Lithium can have harmful effects at relatively low doses, even potentially fatal ones, and there is no evidence of any positive effect on cognitive function, beyond out of context quotes about increases in hippocampal and pre-frontal cortex volumes, that are erroneously extrapolated and used as the foundation of an ill-considered low dose regiment.
I know of no evidence suggesting that 5-10mg dosages of lithium are potentially toxic, let alone fatal. Most people take lithium for benefits related to mood and neuroprotection, not cognitive enhancement. It is unknown if it induces neurogenesis at these dosages; but if studies showing an increase in white matter are 'out of context' at this dose, then so are concerns about toxicity.
As far as toxicity studies, I'd take a harder look, it's toxic well before it reaches organ necrosis levels, not to meniton the fact that chelates like oratate probably provide more elemental lithium that carbonate, so "5-10mg" doesn't mean much. Patients have been known to exhibit systemic, acute toxicity from relatively low doses of carbonate, within the lower end of prescribed ranges, and paradoxically low serum concentrations. I'd have to dig to find the study I'm thinking of, or better yet put on your detective cap. The purported "neurogenic" effects seem pretty moot considering there has never been a single study linking this neurogensis, which is as far as I can tell deduced from mri volumetric study and not histological examination, to increases on any marker of cognition, and in fact it is known to carry wide-ranging singnal disruption effects, and nowhere is there meaningful evidence that this neurogenesis, once lithium is discontinued, provides a net positive effect. Heck there aren't even rodent studies suggesting this. 0 evidence. The neurogenesis could be in reaction to perceived neurotoxicity, or it could be benign, but even if it were benign, and ultimately beneficial, it's extremely unlikely that 5-10 mg of lithium carbonate would give you that effect. Show me 1 study providing any empirical evidence of lithium as a cognitively beneficial substance, especially long-term benefits (something we can link to any purported benign neurogenesis), and maybe I'll entertain the possibility. Otherwise I'll call the bluff: Lithium is and extremely toxic metal, tolerated long term only in trace levels, and all links to neurogenesis (hippocampal, prefrontal), that I've seen, are volumetric studies and could be the result of a number of things: neurotoxicity, increased blood flow, swelling. And even if it exhibits real, benign neurogenesis, what indicates that these new neurons are healthy and meaningfully integrated into the brain?
As an aside I've taken "low doses" of lithium (oratate) and it made me retarded. I also have 2 friends, and a breastful of studies indicating that carbonate absolutely destroys cognition. I've taken carbonate at 300mg, which is not a mild dose but supposedly equivalent to a middling dose of oratate, and it made me a zombie for 3 hours. If it's not clear already, I think it's a terrible idea, and it definetely is potentially dangerous, even at low doses. Heck you know what else increases neurogenesis? Scolpamine, and about a million other toxic substances, head injury, epilepsy, hypothermia, and no one would consider any of those things remotely beneficial for processing efficiency or capacity.
