To further validate their work, they also looked at this same relationship with autism and major depressive disorder diagnoses. They found that the findings were specific to ADHD, with no associations observed between the other two disorders.
"The reported association is intriguing, but it raises many questions that have no answers," commented Dr. John Krystal, Editor of Biological Psychiatry. "Do sunny climates reduce the severity or prevalence of ADHD and if so, how? Do people prone to develop ADHD tend to move away from sunny climates and if so, why?"
As with all scientific research, further work is necessary, including a prospective replication of these findings. It is also important to realize that this data reflects only an association - not a causation - between ADHD and solar intensity levels so worried parents should not start planning cross-country moves.
However, these findings do have significant implications, explains Dr. Arns. "From the public health perspective, manufacturers of tablets, smartphones and PCs could investigate the possibility of time-modulated color-adjustment of screens, to prevent unwanted exposure to blue light in the evening."
"These results could also point the way to prevention of a sub-group of ADHD, by increasing the exposure to natural light during the day in countries and states with low solar intensity. For example, skylight systems in classrooms and scheduling playtime in line with the biological clock could be explored further."
|Contact: Rhiannon Bugno|