What is it about?
The 21st century has witnessed the discovery of many different gene variants associated with ADHD. These discoveries are already providing a start-point to investigating biology and identifying new treatments but it will take time for this to happen. The purpose of this selective review is to consider genetic findings from the last 5 years and their implications for how we view ADHD and future clinical practice. Recent discoveries reveal the strong genetic overlaps between ADHD and Autism Spectrum Disorder (ASD), as well as Intellectual Disability (ID). Thus it is welcome that previous diagnostic exclusion criteria for ADHD in the presence of ASD have been removed from new diagnostic systems. Overall ADHD appears to behave very much like childhood neurodevelopmental disorders like Autism and Intellectual disability in terms of its genetic profile. However it also shows gene overlaps with other disorders like depression and we do not know why and this needs to be further examined. ADHD while usefully conceptualized as a disorder in clinical practice, can be viewed as a trait like blood pressure and high blood pressure. Recent genetic studies show that those with carry on having ADHD in adult life seem to have a stronger genetic burden. Routine genetic testing for rare gene mutations in ADHD is not yet recommended although guidelines in many countries recommend testing those with mild intellectual disability or autism so practice could change if there are medical implications but this will only apply to a minority. The common gene variants are only weakly predictive so testing has limited clinical value at present as do pharmacogenetics tests.