I've been through several layoff cycles now and every time, as soon as first rumors hit, the office turns into a competition. People stop sharing, managers get cagey, friends watch each other sideways...you get the picture. It's exhausting.
My approach now is simple. I assume my number might come up and keep my options open. I update the resume every month and if it happens, it happens. Being prepared is the only way to stay sane.