On the physiological function of lithium from a psychiatric view point.
Lithium is a naturally occurring alkali metal, which living organisms ingest from dietary sources and which is also present in trace amounts in the human body. In much higher concentrations, lithium is effective as a medication for mania and mood swings including manic depressive disorders. Many studies have shown that a deficiency in 'endogenous' lithium, i.e. lithium in food and drinking water, can lead to defects in growth and development in animals and to grave psychopathological problems in humans. It is therefore conceivable that lithium has an essential function in the physiological regulation of mood and that a subgroup of pathological mood disorders cause a bodily requirement for drastically higher concentrations of lithium in compartments. Taking lithium long-term could have a prophylactic effect on this kind of change in bodily requirements.