Robert Wittke, left, 24, who says he has been looking for full or part-time work for about two months, talks with manager Jennifer Kaminsky as he fills out an application at Snelling Staffing Services in East Brunswick, N.J., Friday, Sept. 5, 2008. The nation's unemployment rate zoomed to a five-year high of 6.1 percent in August as employers slashed 84,000 jobs, dramatic proof of the mounting damage a deeply troubled economy is inflicting on workers and businesses alike. (AP Photo/Mike Derer)
Working loads of overtime could cost you your head. A new study found logging more than 55 hours a week on the job takes a mental toll on middle aged workers. Research showed those employees scored lower on vocabulary and reasoning tests than people with 40 hour work weeks.