Four years ago, my son Rupert, then 19, told me he occasionally took cannabis. I wasn’t worried. Rites of passage and all that. Don’t progress to heroin, I warned, recalling funerals of fallen friends.

In January 2017, Rupert took his life in violent fashion. In his last six months, he had suffered the full gamut of psychosis: schizophrenia, false memories, a God complex, paranoia and visitations. Of his visitations, the friendliest was from a comedian (Jimmy Carr) who at least made him laugh. The rest of his mind’s gatecrashers were ghouls.

Rupert’s descent from an artistic, athletic, easy-going boy into the vortex of psychosis began, his mother and I believe, during his second year at Essex University – in common with nearly every campus in the country, an easy place to obtain recreational drugs.

He was seen first by the family doctor and then a psychiatrist who prescribed medication for suspected drug-induced psychosis. After returning to university and threatening suicide, however, intervention followed and he was sectioned.