Study Indicates Majority Of Patients Complaining Of Insomnia Are Diagnosed With A Mental Disorder

PULLMAN, Wash. -- A new study by Washington State University researchers reveals that among patients seeking medical care for insomnia, more than half were diagnosed with a mental disorder. The most common diagnosis was depression.

The findings are published in the August 1999 issue of the scientific journal, Clinical Drug Investigation.

The researchers found that over 3 million patients per year visited a physician complaining of insomnia as one of the reasons for scheduling an office visit. Over one-third of these patients stated that insomnia was the primary reason for requesting an office visit.

Among these patients, only 18.8 percent were diagnosed with insomnia, and just 16.1 percent were prescribed a sedative/hypnotic agent as a sleeping aid.

In contrast, 57.4 percent of patients were diagnosed with a non-sleep related mental disorder. The most common mental disorder was depression, which was diagnosed in 31.7 percent of patients.

Because insomnia is a symptom or condition and not a disease, treatment is to be targeted at the underlying cause of the problem, such as depressive illness.

The authors note that over one-third of the U.S. adult population experiences insomnia each year. However, results from this study indicate that less than 5 percent of patients with sleep difficulties actually seek the care and advice of a physician.

In the U.S., sleep disorders are associated with increased expenditures for health care services and a reduced quality of life.

The article, "Psychiatric Comorbidity and Pharmacological Treatment Patterns among Patients Presenting with Insomnia: An Assessment of Office-Based Encounters in the USA in 1995 and 1996," reports results of a study conducted by Tracy L. Skaer, B.Pharm., Pharm.D. and colleagues in the Pharmacoeconomics and Pharmacoepidemiology Research Unit at WSU. Skaer is an associate professor of pharmacy practice, and assistant dean in the WSU College of Pharmacy.

Skaer and her colleagues drew data for their analysis from the 1995 and 1996 U.S. National Ambulatory Medical Care Survey. They examined physician office visits among persons age 18 years or older.

Other researchers participating in the study include David A. Sclar, B.Pharm., Ph.D.; Linda M. Robison, M.S.P.H.; and Richard S. Galin, M.D. All are with the Pharmacoeconomics and Pharmacoepidemiology Research Unit in the WSU College of Pharmacy.

Sclar is also a member of the research faculty at the Washington Institute for Mental Illness Research and Training. Galin is also affiliated with the University of California at Los Angeles Neuro-Psychiatric Institute.