He did read survivalist books, there was a book about identifying edible plants he had with him when he died. He even hired a botany/foraging tutor I believe. Ultimately though it's kinda the same thing, if he was suicidal, it would have been because of the abuse, most likely. Personally, I don't think it holds much water, suicidal people don't typically go off and live in the wilderness to starve to death, they usually kill themselves a bit more directly, whereas "mediocre rich white boy vastly overestimates his own wilderness survival abilities and is horribly unprepared for the reality of living off the land" is highly credible