Italian researchers have developed a nasal spray using gold nanoparticles to deliver lithium directly to the brain. The approach could open safer treatment possibilities for bipolar disorder, Alzheimer’s disease, and viral brain infections.

Lithium has been one of the most reliable treatments for bipolar disorder for decades. But when taken orally, it can cause side effects, especially on the kidneys and thyroid. Their research shows that gold nanoparticles can transport lithium across the nasal passage directly into the brain.