Musician Nick Cave's teenage son took LSD before he fell off a cliff in Brighton, England, an inquest has heard.
Arthur Cave, 15, was found with multiple injuries on the underpass of Ovingdean Gap in July. He died later at the Royal Sussex County Hospital.
Sussex Police said his death was not suspicious, and the coroner ruled it was "accidental".
Cave, 58, is an Australian songwriter and is best known as lead singer of Nick Cave and the Bad Seeds.
Cave and his wife Susie Bick are at the hearing which is being held in front of Brighton senior coroner Veronica Hamilton-Deeley in southern England.
The inquest heard Arthur had taken LSD with a friend and he was seen "staggering" on his own before he fell off the cliff.
Members of the public tried to resuscitate him after he was found lying on the ground without any shoes or socks on.
During evidence given by pathologist Dr Simi George, Ms Hamilton-Deeley asked: "The history you had was that LSD was used?"
Dr George replied: "Yes."
The cause of death was given as "multiple traumatic injuries due to a fall from a height".
Recording a conclusion of accidental death, Ms Hamilton-Deeley, said: "I expect the decision and planning to take LSD, or a hallucinogenic drug likely to be LSD, was made on the spur of the moment.
"It's clear he could not know what was real and what was not real.
"It's completely impossible to know what was in Arthur's mind and what he was seeing."
In a statement issued after the inquest, the Cave family said they had been "overwhelmed" by the messages of support from people "in Brighton and beyond".
It read: "Arthur was a wonderfully unruly, creative and free-spirited young man with an infectious, happy, funny daredevil nature.
"He loved his friends and family, idolised his twin brother Earl and was never far from his side."