Also, could the relationship be reversed. They suggest high anxiety -> less sleep -> higher mortality. But it seems possible high anxiety would also directly li

Also, could the relationship be reversed. They suggest high anxiety -> less sleep -> higher mortality. But it seems possible high anxiety would also directly link to higher mortality (e.g., high blood pressure), and sleep would be a side effect, not the cause of higher mortality. Same with low conscientiousness (exercise less, eat junk food).