Why does lithium work against bipolar disorder?

In modern times we tend to think of lithium as powering smartphones and cars, yet its historical fame comes from its role as a mood stabilizer.

Lithium was first used as a treatment for bipolar disorder in 1949. Yet despite decades of research and drug development, this simple medication remains the gold standard for treating one of the most complex psychiatric conditions. But why?

According to Becci Strawbridge, a senior lecturer in psychological medicine at King's College London, lithium's simplicity could be what helps it cut through the complexity of bipolar disorder, a lifelong disorder that affects about 36 million people worldwide.

Clinically, bipolar disorder is defined as a mood disorder characterized by specific, lasting changes to a person's mood and energy levels. Depending on the type of bipolar disorder, individuals can experience man...