Testing the evolutionary advantage theory of attention-deficit/hyperactivity disorder traits

Is There a Relationship Between ADHD and COVID-19 Prevalence and Mortality Indices? An Analysis of Data From 156 Countries

OBJECTIVE

To examine the relationship between nation-level prevalence of ADHD and COVID-19 prevalence and mortality indices.

METHOD

Associations between nation-wise estimated prevalence, crude mortality rates and case-fatality ratios for COVID-19 and estimated prevalence rates for ADHD were examined, controlling for medical conditions known to be associated with COVID-19 outcome, as well as demographic, climate-related, and economic variables.

RESULTS

Prevalence of ADHD was positively correlated with COVID-19 prevalence and crude mortality rates on bivariate analyses, though the strength of this association was low. On multivariate regression, prevalence of ADHD was negatively associated with COVID-19 prevalence and crude mortality rates, though only the former finding was statistically significant.

CONCLUSION

The association between ADHD and COVID-19 prevalence and mortality at a national level is inconsistent, modest, and may be largely due to confounding factors such as age, lifestyle factors, and medical comorbidities.

Genetics in the ADHD Clinic: How Can Genetic Testing Support the Current Clinical Practice?

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder with a childhood prevalence of 5%. In about two-thirds of the cases, ADHD symptoms persist into adulthood and often cause significant functional impairment. Based on the results of family and twin studies, the estimated heritability of ADHD approximates 80%, suggests a significant genetic component in the etiological background of the disorder; however, the potential genetic effects on disease risk, symptom severity, and persistence are unclear. This article provides a brief review of the genome-wide and candidate gene association studies with a focus on the clinical aspects, summarizing findings of ADHD disease risk, ADHD core symptoms as dimensional traits, and other traits frequently associated with ADHD, which may contribute to the susceptibility to other comorbid psychiatric disorders. Furthermore, neuropsychological impairment and measures from neuroimaging and electrophysiological paradigms, emerging as potential biomarkers, also provide a prominent target for molecular genetic studies, since they lie in the pathway from genes to behavior; therefore, they can contribute to the understanding of the underlying neurobiological mechanisms and the interindividual heterogeneity of clinical symptoms. Beyond the aforementioned aspects, throughout the review, we also give a brief summary of the genetic results, including polygenic risk scores that can potentially predict individual response to different treatment options and may offer a possibility for personalized treatment for the therapy of ADHD in the future.