Psychedelics in Medicine
A research team at Johns Hopkins Medical School “are studying whether psilocybin-assisted psychotherapy can help people with cancer cope with the psychological impact of their condition”:
Following up on our first studies with healthy volunteers, we are reactivating research into the promising application of brief counseling assisted by psilocybin for persons with a diagnosis of cancer. Studies in the 1960’s and early 1970’s suggested that this intervention could decrease anxiety, depression, interpersonal isolation, fear of death, and preoccupation with pain, thus enabling persons to live whatever time remained more fully.
Psychedelics seem to have pretty observable effects when used to explore inwards – I don't know that they'll get you in touch with the external world in any deeper way, but they sound like a very effective way of exploring your own mind.