This study examined the long-term effects of employment on mental health costs, finding that steady employment was associated with a reduction in service utilization and, in turn, cost.  The authors also discuss the policy implications of the findings. 

Bush, P. W., et al. (2009). The long-term impact of employment on mental health service use and costs for persons with severe mental illness. Psychiatric Services, 60(8): 1024-31. DOI:10.1176/appi.ps.60.8.1024. http://psychservices.psychiatryonline.org/cgi/content/abstract/60/8/1024

Authors: Philip W. Bush, Robert E. Drake, Haiyi Xie, Gregory J. McHugo, William R. Haslett