Oh okay....here we go....
"Feilding was a proponent of utilising the cognitive effects of cannabis since the 1960s. She experimented with trepanning, drilling a hole into her skull in 1970 to expose the dura mater, a technique used in some cultures to treat mental illness, and considered by some to provide a calming effect or a higher state of consciousness.[2] She was also a proponent of the use of LSD to trigger long-term improvements in creativity"
That pretty much explains it.