Using lithium to treat children with bipolar disorder is safe and effective in the short term, the results of a new study indicate. Bipolar disorder, previously referred to as manic-depressive illness, is a brain disorder that causes unusual shifts in mood, energy, and activity levels, and patterns of high and low moods.

A great deal of controversy surrounds diagnosing (and treating) children with bipolar disorder. A 2007 study estimated the annual number of children receiving a diagnosis of bipolar disorder increased from 25 per 100,000 (between 1994 and 1995) to 1,003 per 100,000 (between 2002 and 2003) — a 40-fold increase. While some argue this sudden increase simply reflects overdue recognition of this disorder in children, others believe the disorder is both poorly defined and commonly known. Combined, these factors account for increasing misdiagnoses. The Juvenile Bipolar Research Foundation notes that the dates in this study fall prior to and after the creation of a new American Psychiatric Association classification for the disorder. The one given to most children: BP-NOS or Bipolar Disorder Not Otherwise Specified.

New Classification, Same Treatment?

A BP-NOS diagnosis, according to the National Institute of Mental Health (NIMH), is usually given to patients who stray beyond the normal range of behavior even though symptoms do not match the criteria for bipolar I or bipolar II. These diagnoses differ in terms of severity, but both involve similar mood changes, with each mood lasting a week or more. While the thinking behind this new classification may be nuanced, BP-NOS is often treated exactly the same (and with exactly the same drugs) as bipolar disorder.

Among the drugs prescribed for any category of bipolar disorder, the most common is lithium, which the National Library of Medicine classifies as an antimanic agent. Lithium prevents episodes of mania by decreasing abnormal activity in the brain. The danger with alternating mood cycles, where patients feel happy and frenzied then become depressed, is an increased risk of suicide.

According to the NIMH, lithium (and other mood-stabilizing drugs) are usually the first choice to treat bipolar disorder. And, while lithium has been approved for the treatment and prevention of manic symptoms in children ages 12 and older, doctors may prescribe it on an "off-label" basis to children under the age of 12. However, lithium has only been extensively tested in adults — until now.

Lithium vs. Placebo

To test lithium in children, Dr. Robert Findling, a professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, and his colleagues performed what is commonly considered “the gold standard” in scientific research: a randomized, placebo-controlled study. The participants, 81 patients, ranged in age from 7 to 17.

The experiment began with a washout period for those already taking an ineffective medication. Then, 53 of the patients began a new regimen of lithium at a standard dose, which gradually increased to the maximum dose if mood symptoms did not immediately come under control. The remaining 28 patients received a placebo throughout the eight-week study period.

“Lithium was superior to placebo in reducing manic symptoms in pediatric patients treated for BP-1 [type one bipolar disorder],” wrote the authors of the study.

In fact, patients on lithium experienced far more significant improvements in their symptoms compared to those on the placebo, the researchers observed. Just under half (47 percent) of patients on lithium scored in the range of “very much improved” or “much improved” on a rating scale commonly used to assess the treatment efficacy. That was compared to less than a quarter (21 percent) of those taking the placebo.

Importantly, lithium was not associated with a significant weight gain (unlike commonly prescribed antipsychotic agents), and none of the patients experienced any serious side effects. According to the authors, both these factors increase the likelihood that young patients will take their medication without fail. Going forward, the Johns Hopkins Children’s Center researchers will continue to analyze the long-term safety profile of the drug when used by children and teens.

Source: Findling RL, Robb A, McNamara NK, et al. Lithium in the Acute Treatment of Bipolar I Disorder: A Double-Blind, Placebo-Controlled Study. Pediatrics. 2015.