Lithium is a mood stabiliser, but the exact way that it works is not known. Lithium may work by changing the release of chemicals like dopamine or serotonin in your brain. Taking lithium helps you to have more control over your emotions. It helps you cope better with bipolar mood swings. It may take several weeks to months for lithium to start working. At first you may need to be on other medicines at the same time. These will help you to stay calm. You may need to be in hospital when you start lithium treatment.