Lithium in brain white matter

 Lichtinger's results are surprising: Only in the samples of a depressive patient treated with lithium did he observe a higher accumulation of lithium in the so-called white matter. This is the area in the brain where nerve tracts run. The lithium content in the neighboring grey matter was 3 to 4 times lower. Lithium accumulation in white matter was not observed in a number of untreated depressive patients. This points to the fact that lithium does not work in the space between nerve cells, like other psychotropic drugs, but within the nerve tracts themselves.