OBJECTIVES : Trends indicate an increase in mental illnesses among youths, with research suggesting increases in divorce, electronic media, and focus on extrinsic goals as likely causes. This study examined the rate of mental illness and associated costs in youths living in the U.S. over the past decade.

METHODS : This retrospective analysis utilized the IBM^®MarketScan^®Research Database spanning 2011-2017. Annual samples of children aged 4-17 with continuous enrollment for the entire year were defined; incidence and prevalence rates of mental illness diagnoses were calculated. Children with a single inpatient or outpatient medical claim with a diagnosis code in any of the following categories were classified as having a mental illness: alcohol/substance abuse, depression, anxiety, eating disorders, bipolar, schizophrenia, developmental disorders, attention/conduct disorders, and other mental illnesses. Total annual healthcare costs were compared between children with a mental illness and a non-mental illness control population adjusting for age and gender.

RESULTS : From 2011 to 2017, there was a 30.5% increase in the prevalence of mental illness, with rates of affected children increasing from 12.0% in 2011 to 15.7% in 2017. The most common conditions were attention/conduct disorders, anxiety, and depression. Among the mental illnesses examined, anxiety, eating disorders, developmental disorders, and depression presented the greatest increases over the study period at 85%, 69%, 67%, and 56% respectively. Children with a mental illness incurred significantly greater healthcare costs compared to controls in all years assessed, which were 2.5-fold higher in 2017 ($7,087±$33,160 vs. $2,026±$13,985; p< 0.001).

CONCLUSIONS : Mental illnesses diagnoses have increased substantially among Us children over the past decade. The increased healthcare costs incurred by these children place a notable burden on the healthcare system. Estimates from this study are based on billed diagnoses; the true rate of these conditions among children is likely even greater due to undiagnosed cases.