AHRQ overview of hospitalizations related to diagnoses of mental disorders: In 2006 one out of every five hospital stays (21.3%, or 8.4 million stays) involved a mental health condition either as the primary diagnosis (1.4 million stays, or 3.4% of all stays) or the secondary diagnosis (7.1 million stays, or 17.9%), according to a statistical brief released by the Agency for Healthcare Research and Quality (AHRQ). The two leading causes of hospitalizations for mental health conditions were mood disorders (729,500 stays) and schizophrenia (380,600 stays). Together these conditions were responsible for 82% of all stays for which a mental health diagnosis was the principal diagnosis. Common secondary mental health diagnoses included dementia and other cognitive disorders (1.7 million stays, or 24% of all stays with a secondary mental health diagnosis). Anxiety disorders were a secondary diagnosis in 1.3 million stays, or 19%. The average length of stay for hospitalizations involving a mental health condition was greater than for all stays (8.2 days compared with 4.6 days). Hospital charges for mental health hospitalizations were about $3,300 less per day ($1,900 per day compared with about $5,200 per day for all stays). Medicare and Medicaid were the expected payers for six of every ten mental health hospitalizations, and private insurance paid for slightly more than two of ten. About one of every ten stays with a principal mental health diagnosis was uninsured. Rates of mental health hospitalizations were twice as high in the Northeast as in the West. The statistical brief, Hospital Stays Related to Mental Health, 2006, is based on data from the Nationwide Inpatient Sample of the Healthcare Cost and Utilization Project's (HCUP). The statistics were generated from HCUPnet, a free, online query system that provides users with immediate access to the largest set of publicly available, all-payer, national, regional, and state-level hospital care databases from HCUP. The brief is available on the AHRQ Web site at www.hcup-us.ahrq.gov.