Children who have received radiotherapy for a brain tumor can develop cognitive problems later in life. In their studies on mice, researchers at Karolinska Institutet have now shown that the drug lithium can help to reverse the damage caused long after it has occurred. The study is published in the journal Molecular Psychiatry and the researchers are now planning to test the treatment in clinical trials.

Nowadays, four out of five children with a brain tumor survive. In the adult Swedish population, one in 600 people have been treated for childhood cancer, about one third of which were brain tumors. Many of them live with damage caused by the radiotherapy, which can cause deficiencies in memory and learning.

Researchers at Karolinska Institutet in Sweden now show that the memory capacity and learning capability of mice improve if lithium treatment is given after the irradiation of the brain. Mice that were irradiated early in life and then given lithium from adolescence until young adulthood performed just as well as mice who had not been given radiation. The researchers observed an increase in the formation of new neurons in an area that is important to the memory (the hippocampus) during the period in which they received lithium, but their maturity into full nerve cells only occurred once the lithium treatment was discontinued.