ADHD May Develop AFTER Childhood
May 20, 2016
Posted by on
Researchers from the Institute of Psychiatry, Psychology & Neuroscience at King’s College London have found that nearly 70 per cent of the young adults with Attention-deficit/hyperactivity disorder (ADHD) in their study did not meet criteria for the disorder at any of the childhood assessments. Adults with this ‘late-onset’ ADHD had high levels of symptoms, impairment and other mental health disorders.
Published in JAMA Psychiatry, these findings from this UK cohort are confirmed by evidence for adult-onset ADHD world-wide: a study from Brazil will be published by JAMA Psychiatry alongside this research, which also identified a large proportion of adults with ADHD as not having the disorder in childhood. Both the UK and Brazilian studies support previous findings from a New Zealand cohort.
The research sample in the King’s College London study included more than 2,200 British twins from the Environmental Risk (E-Risk) Longitudinal Twin Study. Symptoms of childhood ADHD were measured at the ages of 5, 7, 10 and 12 through mother and teacher reports. Young adults were interviewed at the age of 18 to assess ADHD symptoms and any associated impairments, as well as the existence of other mental health disorders.
Dr Jessica Agnew-Blais from King’s College London said: ‘We were very interested by this large ‘late-onset’ ADHD group, as ADHD is generally seen as a childhood-onset neurodevelopmental disorder. We speculated about the nature of late-onset ADHD: the disorder could have been masked in childhood due to protective factors, such as a supportive family environment. Or it could be entirely explained by other mental health problems. Alternatively, late-onset ADHD could be a distinct disorder altogether. We think it is important that we continue to investigate the underlying causes of late-onset ADHD.”