IMPORTANCE

Children living in poverty are at increased risk of mental health and neurodevelopmental disorders. Little is known about the trends in diagnoses of these disorders among children enrolled in public insurance programs, such as Medicaid, which insure more than 1 in 3 US children.

OBJECTIVE

To provide comprehensive, multistate estimates of changes in the percentage of publicly insured children with mental health and/or neurodevelopmental disorder diagnoses.

DESIGN, SETTING, AND PARTICIPANTS: This serial, cross-sectional study used administrative claims data from 22 states to test trends from 2010 to 2019 in the percentage of publicly insured children aged 3 to 17 years with mental health or neurodevelopmental disorder diagnoses. Regression models included a dummy variable for each year, controlled for child demographics, county-level metropolitan status, median household income, and US Census region. Adjusted risk differences were estimated, with standard errors clustered at the state level.

EXPOSURE

Calendar year.

MAIN OUTCOMES

Any mental health or neurodevelopmental disorder diagnosis in the calendar year, and any diagnosis in 1 of 13 specific diagnostic categories.

RESULTS

A total of 129 306 637 child-year observations (29 925 633 unique publicly insured children) were included. The percentage of publicly insured children with any diagnosed mental health or neurodevelopmental disorder increased from 10.7% in 2010 to 16.5% in 2019; this change remained significant after adjustment for covariates (adjusted risk difference [aRD], 6.7 percentage points [95% CI, 5.0-8.4]). Statistically significant increases were also observed in 9 of the 13 diagnostic categories examined. The largest absolute increases were observed for attention-deficit/hyperactivity disorder (aRD, 2.3 percentage points [95% CI, 1.4-3.3]), trauma- and stressor-related disorders (aRD, 1.7 percentage points [95% CI, 0.9-2.5]), anxiety disorders (aRD, 1.6 percentage points [95% CI, 1.2-2.1]), autism spectrum disorders (aRD, 1.1 percentage points [95% CI, 0.9-1.4]), depressive disorders (aRD, 0.9 percentage points [95% CI, 0.6-1.3]), and other neurodevelopmental disorders (aRD, 2.6 percentage points [95% CI, 1.8-3.5]).

CONCLUSIONS AND RELEVANCE

The percentage of publicly insured children receiving any mental health or neurodevelopmental disorder diagnosis significantly increased between 2010 and 2019, with increases observed for most diagnostic categories examined. These findings highlight the need for access to appropriate services in safety net systems and other settings that serve this population.