Press Release

"We are pleased that the results of the BRITE trial indicate that early changes in frontal EEG signals carry important information about future clinical response, as this reinforces our confidence that an EEG-based biomarker has the potential to help clinicians improve the care of patients suffering from depression," said Andrew Leuchter, M.D., professor of Psychiatry at the Semel Institute for Neuroscience and Human Behavior at UCLA, principal investigator for the trial, and chair of Aspect's Neuroscience Advisory Board.

The BRITE trial was conducted in collaboration with leading investigators from 10 facilities across the United States and enrolled 375 patients. Patient response was defined by researchers as a 50 percent improvement in depression symptoms as measured by the Hamilton Depression Rating Scale (HAM-D) after seven weeks of treatment, and remission was defined as recovery from depression (HAM-D less than 7) after seven weeks of treatment. In the BRITE study, ATR at one week predicted response and remission with 74 percent accuracy in subjects treated for seven weeks with escitalopram, which was statistically significant. BRITE study results also suggest that Aspect's technology may help clinicians expedite the process of identifying the most effective type of antidepressant drug therapy for their patients suffering from depression.

"We believe that having an early marker for response or remission will help clinicians rapidly identify the most appropriate medication for their patients and shorten the time needed to achieve successful treatment. Our hope is that this could help eliminate the lengthy and frustrating search for effective treatment, as well as potentially encourage adherence to a treatment plan," said Dr. Leuchter.

Following completion of the BRITE trial, Aspect initiated work with researchers at the Medical University of South Carolina (MUSC) to model the potential economic benefits of the ATR biomarker for health insurers and employers. Early findings from this effort indicate that the use of ATR may provide a cost effective method for individualizing care for patients with major depression. "By applying the BRITE data to cost models of depression care, we demonstrated that the ATR biomarker could be a cost effective measure that meets health economic definitions of good value for new medical technologies," said Kit N. Simpson, DrPH, Professor at the Center for Health Economic and Policy Studies at MUSC. Abstracts highlighting these preliminary economic analyses will be presented at the ISPOR meeting this week as well as at the New Clinical Drug Evaluation Unit (NCDEU) conference in Phoenix, AZ May 27-30.

In the United States alone, an estimated 15 million people experience a depressive episode each year, and nearly 17 percent of adults will experience major depression in their lifetime. The majority of patients being treated for major depression are prescribed a selective serotonin reuptake inhibitor (SSRI), such as escitalopram (a commonly prescribed first-line antidepressant). Research has shown that the majority of patients seeking treatment for depression will not respond adequately to the first antidepressant treatment they are prescribed, and in many cases, it can take months before a patient responds to antidepressant medication and feels better. While treatment with antidepressants will eventually lead to remission in the majority of treated patients, many will require a second, third or fourth treatment before experiencing relief.

Aspect plans to initiate a second confirmatory study named the RAPID trial (Rapid Assessment for Prediction of Improvement in Depression) seeking to prospectively validate the ATR biomarker as a predictor of antidepressant treatment response. The trial is being designed based on input from investigators as well as feedback from the U.S. Food and Drug Administration and is expected to begin mid-year 2008.

About Aspect Medical Systems, Inc.

Aspect Medical Systems, Inc. (NASDAQ: ASPM) is a global market leader in brain monitoring technology. To date, the Company's Bispectral Index (BIS) technology has been used to assess approximately 26 million patients and has been the subject of more than 3,300 published articles and abstracts. BIS technology is installed in approximately 80 percent of hospitals listed in the July 2007 U.S News and World Report ranking of America's Best Hospitals and in approximately 60 percent of all U.S. operating rooms. In the last twelve months BIS technology was used in approximately 19 percent of all U.S. surgical procedures requiring general anesthesia or deep sedation. BIS technology is available in more than 160 countries. Aspect Medical Systems has OEM agreements with nine leading manufacturers of patient monitoring systems. The company is also investigating how other methods of analyzing brain waves may aid in the diagnosis and management of neurological diseases, including depression and Alzheimer's disease. For more information, visit Aspect's Web site at http://www.aspectmedical.com.

Safe Harbor Statement

Certain statements in this release are forward-looking and may involve risks and uncertainties, including statements with respect to the potential ability of the Company's brain assessment technology to rapidly predict the effectiveness of antidepressant medications and expedite the process of identifying effective antidepressant drug therapy, the anticipated benefits of the BRITE trial, the Company's anticipated timing with respect to initiating a confirmatory trial mid-year 2008 as a final step toward preparing an FDA submission for the technology and the Company's belief that it can develop a practical, easy-to-use brain assessment device to help clinicians optimize care for patients suffering from depression. There are a number of factors that could cause actual results to differ materially from those indicated by these forward-looking statements. For example, the Company may not be able to successfully develop and/or obtain required regulatory approvals for its products under development for the diagnosis, management and treatment of neurological diseases, such as depression and Alzheimer's disease, achieve widespread market acceptance of any such products that it may develop or to compete with new products or alternative techniques that may be developed by others. In addition, the Company may not achieve comparable or confirmatory results in later trials, including its planned RAPID trial, as those achieved in earlier studies. There are other factors that could cause the Company's actual results to vary from its forward-looking statements, including without limitation those set forth under the heading "Risk Factors" in the Company's Annual Report on Form 10-K for the year ended December 31, 2007 as filed with the Securities and Exchange Commission. In addition, any forward-looking statements represent the Company's views only as of the date of this press release and should not be relied upon as representing the Company's views as of any subsequent date. While the Company may elect to update forward-looking statements in the future, it specifically disclaims any obligation to do so, even if its expectations change. Therefore, you should not rely on these forward-looking statements as representing the Company's views as of any date subsequent to the date of this press release. Aspect, Bispectral Index and BIS are registered trademarks of Aspect Medical Systems, Inc. All other trademarks, service marks and company names are the property of their respective owners.

SOURCE: Aspect Medical Systems, Inc.

Aspect Medical Systems
Emily Anderson, 617-559-7032
eanderson@aspectms.com
Media Relations