San Antonio – Psychiatric comorbidities are present in two-thirds of children with restless legs syndrome, according to a study.
Moreover, multiple psychiatric diagnoses were extremely common in this retrospective study of 376 children aged 2–18 years who met National Institutes of Health consensus criteria for definite or probable restless legs syndrome (RLS). Indeed, boys with RLS were actually more likely to have two or more psychiatric diagnoses than a single one. Multiple psychiatric comorbidities also were quite common in girls with RLS, reported Dr. Samuel J. Pullen of the Mayo Clinic, Rochester, Minn.
Attention-deficit/hyperactivity disorder (ADHD) has been shown in other studies to be common in children with RLS. That was the case in this large series as well, with 1 in 4 of the youths carrying a diagnosis of ADHD.
However, other psychiatric comorbidities were common in these patients, too. This observation constitutes a novel contribution to the field, as previously there has been uncertainty surrounding the rates of psychiatric disorders other than ADHD in children with RLS, according to Dr. Pullen.
Mood disorders were present in 21% of the youths with RLS, anxiety disorders in 12.8%, and disruptive behavior disorder in 10.6%.
ADHD and disruptive behavior disorder were more than twice as frequent in boys as in girls with RLS. Mood disorders were more common in girls.
Two psychiatric diagnoses were present in 27.8% of boys and 19.9% of girls. Three or more psychiatric diagnoses were carried by 15.6% of boys and 7.1% of girls.
Many of the children received multiple trials of psychotropic medications during the course of their treatment. This is concerning, as other studies have linked these drugs to worsening RLS symptoms, Dr. Pullen noted.
The mean serum ferritin level in the study population was 27.8 ng/mL.
Twelve of 15 study participants who underwent psychogenomic profiling displayed genetic derangement at one of three cytochrome P-450 alleles known to be associated with ultrarapid metabolism of psychotropic drugs. This may be associated with increased susceptibility to drug side effects–such as worsening of RLS symptoms. Dr. Pullen indicated that he and his coinvestigators plan further studies of this phenomenon.
The chief take-away point from this 376-patient study, he added, is that sleep specialists should inquire about psychiatric comorbidities in their patients with childhood RLS, while child psychiatrists should ask their patients about symptoms of RLS, a treatable comorbidity.
Dr. Pullen reported having no relevant financial disclosures.