While attention deficit hyperactivity disorder (ADHD) and sleep problems have always been considered separate issues, new research strongly suggests that the two are related. Scientists are now exploring the concept that most ADHD cases may be caused by a lack of regular circadian sleep.
The developing theory that these two conditions are interrelated will be presented by Professor Sandra Kooij at the European College of Neuropsychopharmacology (ECNP) Conference in Paris.
“There is extensive research showing that people with ADHD also tend to exhibit sleep problems,”said Kooij. “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.”
Kooij explained that when day and night rhythm is disturbed, the timing of several physical processes is interrupted. Sleep, temperature, movement patterns, timing of meals, and other activities can all be disturbed by the disruption of the body’s internal clock.
“If you review the evidence, it looks more and more like ADHD and sleeplessness are 2 sides of the same physiological and mental coin,” said Kooij.
ADHD is associated with many sleep-related disorders including restless-leg syndrome, sleep apnea, and the circadian rhythm disturbance. 75 percent of children and adults with ADHD have irregular sleep patterns where the physiological sleep phase is delayed by 1.5 hours. Core body temperature changes associated with sleep are delayed as well, which reflects melatonin changes.
Another link between sleep disorders and ADHD is that people with ADHD often show greater alertness in the evening, which is the opposite of what is found in the general population. ADHD sufferers can benefit from taking melatonin in the evening or bright light therapy in the morning to help reset the circadian rhythm.
The danger for people who experience chronic late sleep is that they accumulate sleep debt. Chronic sleep debt is associated with obesity, diabetes, cardiovascular disease, and cancer. All of these health consequences may be partially preventable by resetting the sleep rhythm.
“We don’t say that all ADHD problems are associated with these circadian patterns, but it looks increasingly likely that this is an important element,” said Kooij.
“If the connection is confirmed, it raises the intriguing question: does ADHD cause sleeplessness, or does sleeplessness cause ADHD? If the latter, then we may be able to treat some ADHD by non-pharmacological methods, such as changing light or sleep patterns, and prevent the negative impact of chronic sleep loss on health.”
By Chrissy Sexton, Earth.com Staff Writer