Det Insp Sarah Weeks said the force downloaded information from Archie's phone on June 13th.
She said there was no evidence of him filming any video on the day he was found unconscious, and there were no photographs or videos on the phone to suggest he had been taking part in an online challenge.
Officers said they found YouTube and Internet searches related to his interests, like mixed martial arts.
Following a "full forensic download" of the phone, Det Insp Sarah Weeks said: "There are a series of messages which reflect Archie's mood."This has only been received this morning so we will look to prepare a full report."
The coroner said: "It's low mood we're looking at here, very low mood."
Earlier this year, the pre-inquest heard that Archie's provisional cause of death was a "catastrophic" brain injury, and that "multiple professionals" and second opinions confirmed he had suffered "severe irreversible brain injury."A full inquest is to be held in Chelmsford on February 7th.
