This paper addresses the role of lithium both in its geological origins and in its therapeutic use in psychiatry, highlighting the implications of its extraction and medical application. Under standard conditions it is the lightest solid element on the periodic table. Like all alkali metals, lithium is highly reactive and flammable and is stored in mineral oil. Lithium is widely found in the Earth's crust, but it does not occur as a specific mineral, that is, with a chemical composition and defined crystal structure, allowing its extraction in isolation in mineral deposits. In Brazil, it is always a component that forms the crystal structure of lithiniferous pegmatite minerals, such as spodumene (the only economically exploitable for lithium extraction), petalite, amblygonite, and elbaite, related to endogenous processes. In the exogenous environment, it occurs as a constituent of salt flats in Andean countries such as Argentina, Chile, and Bolivia. Its geological exploration is related to specific mining processes, with concentration by electrolysis. Lithium has many applications, from lubricating grease, alloy additions, in particular for Aluminum and Magnesium alloys, to glazes for ceramics, and finally Lithium batteries. In the field of psychiatry, lithium has established itself as an essential drug for the treatment of bipolar disorder, acting as a mood stabilizer by modulating neurotransmitters and neuronal processes. Thus, the present study seeks not only to highlight the geological processes involved in lithium extraction, but also to discuss the therapeutic contributions and clinical challenges associated with its use.