Distribution of lithium in the brain plays key role in depressive disorders Depressive disorders are among the most frequent illnesses worldwide. The causes are complex and to date only partially understood. The trace element lithium appears to play a role. Using neutrons of the research neutron source at the Technical University of Munich (TUM), a research team has now proved that the distribution of lithium in the brains of depressive people is different from the distribution found in healthy humans. Lithium is familiar to many of us from rechargeable batteries. Most people ingest lithium on a daily basis in drinking water. International studies have shown that a higher natural lithium content in drinking water coincides with a lower suicide rate among the population.