Knuth is great, but if we are going to attribute this derivation, we have to go far longer back in time. De Moivre was the first to derive a closed formula for the Fibonacci numbers, and he did so by "inventing" generating functions. I only have wikipedia as a source right now, as I have most of my math books, including the few on the history of mathematics I have, in boxes :)
That work load should have no effect on risk of depression sounds downright whack. In none of the summaries of the three linked articles do I see that part of the claim documented by their data.
Below are the "results" sections from the summaries of the two non-saliva articles among the 3 referenced in the posted "article".
From "A two-year follow-up study of risk of depression according to work-unit measures of psychological demands and decision latitude."
RESULTS:
The OR for depression according to psychological demands was 1.07 [95% confidence interval (95% CI) 0.42-2.49] for every unit of change on a 5-point scale. The corresponding OR for decision latitude was 1.85 (95% CI 0.55-6.26). No interactive effects of psychological demands and decision latitude were observed.
CONCLUSION:
These findings suggest that low decision latitude may predict depression, but confidence intervals are wide and findings are also compatible with no increased risk.
From "Work-unit measures of organisational justice and risk of depression--a 2-year cohort study."
RESULTS:
Working in a work unit with low procedural justice (adjusted ORs of 2.50, 95% CI 1.06 to 5.88) and low relational justice (3.14, 95% CI 1.37 to 7.19) predicted onset of depression.
CONCLUSIONS:
Our results indicate that a work environment characterised by low levels of justice is a risk factor for depression.