EXPERT ANALYSIS FROM THE ANNUAL CONGRESS OF THE EUROPEAN COLLEGE OF NEUROPSYCHOPHARMACOLOGY
PARIS -- Severely irritable children and children with bipolar disorder show distinct differences--and some similarities, according to longitudinal data, family studies, and recent imaging findings.
The notion that bipolar disorder in children is characterized not by manic and depressive episodes but by very severe, chronic irritability and attention-deficit/ hyperactivity disorder (ADHD) has become popular in the United States in recent years but doesn't hold up to scientific scrutiny, Dr. Ellen Leibenluft said at the meeting.
ADHD is common, and irritability is common within ADHD. As this new way of diagnosing pediatric bipolar disorder gained currency, U.S. diagnoses increased 40%-400% in the past decade, depending on which study you looked at, said Dr. Leibenluft, chief of the section on bipolar spectrum disorders in the emotion and development branch, mood and anxiety program of the National Institutes of Mental Health.
In order to investigate these issues, she and other researchers defined a syndrome called severe mood dysregulation. These are children with chronic irritability (not episodic, as in classically defined bipolar disorder), with baseline anger or sadness and increased reactivity to negative emotional stimuli at least three times per week and in two or more settings (such as the home and school) They have ADHD symptoms that overlap with "B" mania criteria. Clinically, they are the most severely impaired, irritable children with ADHD or oppositional-defiant disorder.
The distinction between bipolar disorder and severe mood dysregulation has important implications for treatment. If an assumption is made that they are the same disorder, a physician might treat with medications for bipolar disorder such as antipsychotics or anticonvulsants.
However Dr. Leibenluft presented data suggesting that it may make more sense to think of children with severe mood dysregulation as having ADHD, anxiety, and depression, in which case a consideration might be made to treat with stimulants and serotonin reuptake inhibitors (SRIs), which would be contraindicated in bipolar disorder.
A trial of the latter approach is underway.
"We don't know yet if these chronically irritable children respond well to stimulants and SRIs,but at least you wouldn't shy away from that the way you would if you thought these children had bipolar disorder," she said.
If severe mood dysregulation is a form of bipolar disorder, these children could be expected to develop mania as they grow up, but that's not what happens, Dr. Leibenluft said. One longitudinal analysis compared 54 children with severe mood dysregulation and 1,366 without the syndrome who were assessed at ages 8-10 years and again at age 18. The children with severe mood dysregulation had more than a sevenfold higher risk for developing major depressive disorder but were not at significantly higher risk for mania or bipolar disorder (Biol. Psychiatry 2006;60:991-7).
A separate, community-based study assessed 776 children at age 14 years and followed them to age 33. Chronic irritability in adolescence did not predict mania but did predict a 33% higher risk for major depression, a 72% higher risk for generalized anxiety disorder, and an 81% higher risk for dysthymia (Am. J. Psychiatry 2009;166:1048-54). …