If you wish to know more about the benefits through therapeutic approaches, I highly recommend Prof. James Fadiman's book titled 'The Psychedelic Explorer's Guide'. It is a rather large resource based on Fadiman's involvement in LSD trials before research was halted abruptly and without warning, and is as close to a scientific approach to developing better pathways to preferred thought processes (through the use of psychedelics mainly LSD) that I am aware of.
Other resources include a therapeutic handbook, provided to health professionals such as psychiatrists prior to the illegalisation of LSD. This can be found on Erowid, alongside other documents that have survived.