A 44-year-old man died from an accidental drug overdose, an inquest heard.
Dale Kipping was found dead at his home in Garratts Way, High Wycombe, on December 10 after his family became concerned for his welfare.
A post mortem gave the cause of death as codeine toxicity, with the examination showing levels of codeine and paracetamol in his system were elevated.
The inquest heard Mr Kipping became confused easily and suffered from bad nightmares.
Coroner Richard Hulett said there was little evidence to show how or why Mr Kipping took more medication than he was supposed to.
He said: "What we don't know is in what circumstances he came to acquire this overdose.
"There's no note, there's no message. The evidence doesn't disclose how or why this came about."
Mr Hulett recorded a short narrative verdict.
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