Lithium, the lightest metal, has transformed our rechargeable-battery technology. But it can also be transformative in the human mind.

Its powers were recognized by early cultures, from the Greeks to Native Americans. And for decades it has been used as a pharmaceutical drug.

Lithium is highly reactive—it’s one of the few metals that will easily burn. If you try to put it out with water, it reacts violently, as it splits off hydrogen gas, which also burns.

When lithium burns, it creates a crimson light—which you’ve seen whenever you’ve watched a fireworks show. Lithium makes their signature red color.

Lithium is so reactive it’s typically stored in mineral oil. But when it enters the human body, often as a much less reactive lithium salt, its incendiary personality does a 180.

In a process we don’t completely understand, it seems to moderate the flow of electricity and promote the overall health of our nervous system. The result is a calming effect.

This has led doctors to prescribe lithium as a successful treatment for bipolar disorder. Studies have even found that cities and towns with higher levels of lithium salts in their groundwater have markedly lower levels of depression, suicide, and violent crime.

A very surprising fact—which has led some scientists to recommend that lithium be considered an essential nutrient. It may be time to take a closer look at this ancient remedy.