Mental Illness Admission Prevalence Highest in Ages 18–44

Richard Franki

August 03, 2021

More mental and/or substance use disorders are ranked among the top-five diagnoses for hospitalized men and women aged 18-44 years than for any other age group, according to a recent report from the Agency for Healthcare Research and Quality.


In 2018, schizophrenia spectrum/other psychotic disorder was the leading primary diagnosis for inpatient stays (251.2 per 100,000 population) in men aged 18-44, while depressive disorders were the third-most common (195.0 stays per 100,000) and alcohol-related disorders were fifth at 153.2 per 100,000, Kimberly W. McDermott, PhD, and Marc Roemer, MS, said in an AHRQ statistical brief.

Prevalence was somewhat lower in women aged 18-44 years, with two mental illnesses appearing among the top five nonmaternal diagnoses: Depressive disorders were second at 222.5 stays per 100,000 and bipolar and related disorders were fourth at 142.0 per 100,000. The leading primary diagnosis in women in 2018 was septicemia, which was the most common cause overall in the age group at a rate of 279.3 per 100,000, the investigators reported.

There were no mental and/or substance use disorders in the top five primary diagnoses for any of the other adult age groups – 45-64, 65-74, and ≥75 – included in the report. Septicemia was the leading diagnosis for men in all three groups and for women in two of three (45-64 and ≥75), with osteoarthritis first among women aged 65-74 years, they said.

There was one mental illness among the top-five diagnoses for children under age 18 years, as depressive disorders were the most common reason for stays in girls (176.6 per 100,000 population) and the fifth most common for boys (74.0 per 100,000), said McDermott of IBM Watson Health and Roemer of AHRQ.

Septicemia was the leading nonmaternal, nonneonatal diagnosis for all inpatient stays and all ages in 2018 with a rate of 679.5 per 100,000, followed by heart failure (347.9), osteoarthritis (345.5), pneumonia not related to tuberculosis (226.8), and diabetes mellitus (207.8), based on data from the National Inpatient Sample.

Depressive disorders were most common mental health diagnosis in those admitted to hospitals and the 12th most common diagnosis overall; schizophrenia, in 16th place overall, was the only other mental illness among the top 20, the investigators said.

"This information can help establish national health priorities, initiatives, and action plans," McDermott and Roemer wrote, and "at the hospital level, administrators can use diagnosis-related information to inform planning and resource allocation, such as optimizing subspecialty services or units for the care of high-priority conditions."

This article originally appeared on, part of the Medscape Professional Network.


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