Restricted access to health care services and medication is associated with overall higher utilization and higher health care costs. Although randomized controlled trials (RCTs) are regarded as the best method of determining whether a treatment strategy does more good than harm, clinical practice improvement (CPI) methods may be a more effective way of achieving superior medical outcomes for the least cost over the course of a patient's care. The Managed Care Outcomes Project, a large-scale CPI study, tracked detailed factors regarding medical care, patients, and outcomes from different managed care settings. Results showed that cost-containment strategies employed by various health maintenance organizations were associated with poor treatment outcomes for patients and in fact increased total health care costs. Psychiatric illnesses were underdiagnosed, and care ranged from patients receiving psychiatric medications without a psychiatric diagnosis to patients with a psychiatric diagnosis receiving no psychiatric treatment at all. Cost-containment strategies appeared to limit psychiatric referrals, frequency of psychiatric visits, and use of certain antidepressants (i.e., selective serotonin reuptake inhibitors). Further, the severity of the primary physical illness in the study population was associated with greater psychiatric illness. The fact that treatment was inconsistent and frequently inappropriate shows the need for better diagnostic and management protocols.