The Prevalence and Incidence of Attention-deficit/Hyperactivity Disorder in the Veterans Health Administration From 2009 to 2016

BACKGROUND: The prevalence and incidence of attention-deficit/hyperactivity disorder (ADHD) have increased substantially among children and adolescents over the past decade; however, little is known regarding trends in adult populations. OBJECTIVE: The objective of this study was to explore trends in the prevalence, incidence, and correlates of adult ADHD in a national sample of veterans receiving care at Veteran Affairs (VA) hospitals and clinics. RESEARCH DESIGN: A retrospective design was used to examine ADHD diagnosed in all VA primary care (PC) and mental health clinics (MHCs) from fiscal years (FYs) 2009 to 2016. Age-adjusted prevalence and incidence were calculated using direct standardization, and Poisson regressions modeled differences in trends between demographic groups. SUBJECTS: All veterans with VA PC or MHC visits during the observation period. MEASURES: ADHD incidence and prevalence, psychiatric comorbidity, neuropsychological evaluation. RESULTS: An annual average of 5.09 million (range: 4.63-5.42 million) VA patients attended a PC or MHC appointment between FY09 and FY16. During this period, age-adjusted annual prevalence increased 258% from 0.23% to 0.84% and incidence increased 240% from 0.14% to 0.48%. Black veterans and older veterans had the lowest prevalence and incidence across all years. Increases in prevalence and incidence occurred across all demographic subgroups. The proportion of patients who had a neuropsychological evaluation within 6 months before or after a new ADHD diagnosis decreased from 12.6% to 10.8% [chi(1)=16.59, P<0.001]. CONCLUSION: Overall increases and demographic differences in adult veterans diagnosed with ADHD suggest a growing need to establish the reliability of diagnostic practices to ensure appropriate and equitable care.