A new study from Columbia University found that middle managers experience nearly twice as much job-related anxiety and depression than employees at the top or bottom of the organizational hierarchy. The study, which was based on a data set from the National Epidemiological Survey on Alcohol and Related Conditions, divided the nearly 22,000 respondents into three groups: owners, who identified as self-employed and earn more than $71,500 per year; managers and supervisors; and blue-collar workers.