<p><strong>BACKGROUND: </strong>Children and adolescents necessitating hospitalization for physical health conditions are at high risk for mental health conditions; however, the prevalence of mental health conditions and symptoms among hospitalized children and adolescents is uncertain. The objective of this study was to determine the proportion of hospitalized children and adolescents who have diagnosed mental health disorders or undiagnosed mental health problems.</p>

<p><strong>METHODS: </strong>In this single-center point prevalence study of hospitalized children between the ages of 4 and 21 years, patients or their parents reported known mental health diagnoses and use of services using the Services Assessment for Children and Adolescent, and they reported patient mental health symptoms using the Pediatric Symptom Checklist, 17-item form (PSC-17).</p>

<p><strong>RESULTS: </strong>Of 229 eligible patients, 119 agreed to participate. Demographic characteristics of patients who enrolled were not statistically significantly different from those of patients who declined to participate. Among participants, 26% (95% confidence interval [CI], 18%-35%) reported a known mental health diagnosis. On the PSC-17, 29% (95% CI, 21%-38%) of participants had a positive screen for mental health symptoms. Of those with a positive screen, 38% (95% CI, 21%-55%) had no known mental health diagnosis, and 26% (95% CI, 12%-43%) had not received ambulatory mental health services in the 12 months before hospitalization.</p>

<p><strong>CONCLUSIONS: </strong>Mental health conditions and symptoms are common among patients hospitalized in a tertiary children's hospital, and many affected patients are not receiving ambulatory mental health services.</p>