Have we lost decades of research on mental health disease because of legal controls on psychedelic drugs? Some scientists claim LSD and MDMA hold the key to treating illnesses like schizophrenia and depression, and are calling for an end to the restrictions on working with them. Others though, say they are too risky to experiment with and the long term dangers are not known. We will speak to experts who argue both sides. Join us at 19:30 GMT.