The American Academy of Neurology presented a study that indicates that Restless Legs Syndrome (RLS) and Attention Deficit Hyperactivity Disorder (ADHD) share a common link. The study confirms that adults with RLS are more likely to have ADHD than adults who are not suffering from the RLS sleep disorder.
Restless Legs Syndrome is a neurological disorder that causes discomfort sensation in the legs during sleep or inactivity. The sensation is relieved by moving the patient's legs or by using external stimulator. Patients with RLS suffer from sleep deprivation and fatigue. Attention Deficit Hyperactivity Disorder is another neurological disorder characterized by hyperactive-impulsive and inattentive behavior exhibited by the patient.
Researchers at the New Jersey Neuroscience Institute at JFK Medical Center tested 56 Restless Legs Syndrome patients and 77 participants who did not show any sign of RLS. They tested both group for possible signs of ADHD. 39% of those in the group with RLS showed signs of potential ADHD. While only 14% of the control group without RLS showed signs of ADHD. Furthermore 21% from the first group with potential ADHD showed signs of "high probability" of ADHD. From the control group, only 4% showed signs of "high probability". Additionally the research indicated that patients with both RLS and ADHD had more severe form of RLS compared to patients with only RLS.
There are two possible explanations for the connection between ADHD and Restless Legs Syndrome. The author of the study Mary L. Wagner, Pharm.D., of Rutgers University explained that the discomfort of the leg caused by RLS provokes the patient to become more hyperactive and unfocused. Furthermore, the sleep disruption or lack of sleep contributed by RLS caused patients to be less attentive during their normal every day activities. This indicates that the two disorders frequently occur together and may be genetically linked.
The second possible explanation that connects RLS and ADHD is lack of dopamine in the brain. Dopamine is a neurotransmitter that is involved in transmitting signals within the brain. The inadequate supply of dopamine in the brain causes patients to have less control over their movements. This explanation in supported by the evidence from research that shows signs of improvement in RLS and ADHD patients treated with drugs that promote dopamine level and activities in the brain.
Researchers warn that this study should not indicate that either disorder causes the other. However they suggest that patient with RLS should get tested for ADHD in order to receive more effective treatment.