Objectives: The objective was to assess the incidence of psychiatric visits among frequent emergency department (ED) users and utilization among frequent psychiatric users.Methods: This was a multicenter retrospective longitudinal study of 1.76 million adult ED visits from acute care hospitals serving the metropolitan San Diego region (2008 through 2010) using nonpublic data submitted to the Office of Statewide Health Planning and Development. Frequent users were defined as having at least four ED visits within 12 consecutive months and were further classified into three groups based on the number of primary psychiatric visits in the same period, as defined by the primary discharge diagnosis (zero, one to three, and four or more visits). Descriptive, univariate, and logistic regression analyses are reported.Results: Patients with at least one primary psychiatric visit were 4.6 (95% confidence interval [CI] = 4.5 to 4.7) times more likely to be frequent ED users compared to patients with none. However, the majority of frequent ED users (80.1%) did not have any primary psychiatric visits; 16.6% of frequent ED users were classified as occasional psychiatric users, and only 3.3% were classified as frequent psychiatric users. Compared to frequent users without primary psychiatric visits, frequent psychiatric users were more likely to be male, non-Hispanic white, and without private insurance and visited the ED more frequently. Frequent psychiatric users also suffered from psychiatric, medical, and substance abuse comorbidity.Conclusions: While patients with primary psychiatric visits were more likely to be frequent users of the ED, only a small percentage of frequent ED users were seen primarily and repeatedly for psychiatric care. However, this small group of frequent psychiatric users visited the ED at a much higher rate than other frequent users and was burdened with both chronic medical and psychiatric conditions. ACADEMIC EMERGENCY MEDICINE 2014;21:1015-1022 © 2014 by the Society for Academic Emergency Medicine E mergency departments (EDs) are becoming increasingly crowded, with the number of ED visits nationwide estimated at 129.8 million in 2010 and rising. 1 Between 1997 and 2007, the number of annual ED visits climbed from an estimated 94.9 million to 116.8 million visits, a 23% increase in just 10 years. 2 ED crowding can lead to negative outcomes, such as longer waiting times, longer overall length of stay, 3,4 and even increased mortality. 5 Much research to date has focused on patient factors contributing to crowding, such as patients who frequently use the ED for care. 6-10 Frequent ED users are a relatively small group of patients who account for a large number of ED visits; as few as 4.5% to 8% of an ED patient population may account for up to 21% to 28% of all ED visits. 11 In addition, frequent ED users are more likely to have chronic medical conditions, drug and/or alcohol problems, and psychiatric disorders. 6,8 Of specific interest in this study was the frequent ED user with a psychiatric...