Business Insider has a thoughtful article charting the increases in disability applicants that can be traced to the Great Recession.
…we estimate that some 695,228 individuals, above and beyond the numbers that might be considered to be normal, have filed for and received Social Security disability insurance benefits in response to the Great Recession in the years from 2008 through 2011. We also note that the timing of the increase in the disability rolls would correspond to when many of these individuals would have exhausted their unemployment benefits, suggesting that going on disability became an alternative to seeking gainful employment for these individuals.