There may be a connection between sleep troubles and attention-deficit/hyperactivity disorder (ADHD), according to an expert at the 30th European College of Neuropsychopharmacology Congress, which was held September 2-5 in Paris, France.
Professor Sandra Kooij is an associate professor of psychiatry at the VU University Medical Center in Amsterdam, the Netherlands, and founder and chair of the European Network Adult ADHD. She explained at the conference that there is a new theory that much of ADHD may be associated with a lack of regular circadian sleep.
"There is extensive research showing that people with ADHD also tend to exhibit sleep problems,” Kooij said in a statement
. “What we are doing here is taking this association to the next logical step: pulling all the work together leads us to say that, based on existing evidence, it looks very much like ADHD and circadian problems are intertwined in the majority of patients.”
The theory is that the day and night rhythm is disturbed, which in turn disturbs the timing of several physical processes, such as movement patterns and timing of meals. Kooij said that the evidence shows “ADHD and sleeplessness are 2 sides of the same physiological and mental coin.”
Research has shown that 75% of patients with ADHD have delayed sleep, plus people with ADHD are often more alert in the evening, which is in contrast with the general population. ADHD is also associated with sleep-related disorders, such as restless-leg syndrome, sleep apnea, and the circadian rhythm disturbance. However, until now, it was largely thought that sleep problems and a person’s ADHD were separate issues.
And while Kooij is clear that not all ADHD problems are associated with circadian patterns, a review of evidence indicates that these patterns are an important element of the disease.
“We are working to confirm this physical-mental relationship by finding biomarkers, such as vitamin D levels, blood glucose, cortisol levels, 24-hour blood pressure, heart rate variability, and so on,” she said. “If the connection is confirmed, it raises the intriguing question: does ADHD cause sleeplessness, or does sleeplessness cause ADHD?”
If sleeplessness causes ADHD, then treatment may be available through nonpharmacological means, such as changing light or sleep patterns.
In the press release, Professor Andreas Reif, of the University Hospital in Frankfurt, and a leader of the European Union CoCA project on ADHD, noted that the connection between sleep issues and ADHD ma help link ADHD to other mental illnesses, such as depression.
"More research into the interconnections between ADHD and the ‘inner clock’ is, thus, very relevant to improve patients' lives and to shed light on the disease mechanism of ADHD,” he said.