H and I suffered a series of horrible layoffs during the recession. We were engineers, so analogous to IT but not exactly.
The longest one lasted a year.
But the repetitive nature of them (I think there were maybe 5 total in 5 years?) was horrible in two ways. 1. We never felt safe and secure. The next one was always looming. 2. Every layoff, the emergency fund would drop as we had to spend some of it, and then when a new job started we would save it up again, just to turn around and empty it again. We never ran the emergency fund out totally, but we never got ahead.
Now H has been in the same job for over 4 years with no layoffs, but it still affects him mentally. I was less affected as my layoff resulted in another job within the same company with no break in pay.