Bipolar Disorder Diagnosis Increases in Children and Adolescents

Outpatient diagnosis of child and adolescent bipolar disorder in the United States has increased by about 40-fold within a 10-year period, according to a report in the September Archives of General Psychiatry. In addition, outpatient diagnosis of adult bipolar disorder has doubled within the same period.

Carmen Moreno, MD, of the Hospital General Universitario Gregorio Marañón in Madrid, and colleagues compared rates of office visits among children and adolescents (19 and younger) and adults (20 and older) with a bipolar disorder diagnosis during the periods of 1994-1995 and 2002-2003. Data were extracted from the National Ambulatory Medical Care Survey, in which physicians or their staffs completed a one-page questionnaire about the demographic, clinical, and treatment characteristics of each visit. Information about visits to other mental health care providers was not included in the survey. A total of 962 visits—154 by children and adolescents and 808 by adults—were included in the analysis, representing 763 visits per 100,000 children and adolescents and 1,602 visits per 100,000 adults.

Physicians made a bipolar disorder diagnosis according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). Psychotropic medications used to treat the patients were classified into five medication categories: mood stabilizers, antipsychotics, antidepressants, benzodiazepines, and stimulants.

Approximately two-thirds of child and adolescent bipolar disorder visits were made by males, whereas two-thirds of the adult bipolar disorder visits were made by females. Among both age-groups, most visits were made by white patients who had previously seen a physician and paid for the visit with private insurance. In most cases, patients received care from psychiatrists. Overall, comorbid mental disorders were as frequent among child and adolescent bipolar disorder patients as they were in adult bipolar disorder patients.

RATES HIGHER IN CHILDREN AND ADOLESCENTS

Among children and adolescents, the estimated annual number of office-based visits resulting in a bipolar disorder diagnosis increased from 25 per 100,000 population in 1994-1995 to 1,003 per 100,000 population in 2002-2003. Among adults, the estimated number of office-based visits with a bipolar disorder diagnosis increased from 905 per 100,000 population in 1994-1995 to 1,679 per 100,000 population in 2002-2003.

Male sex was associated with an increased likelihood of bipolar disorder diagnosis in children and adolescents (odds ratio, 1.93). After controlling for ADHD, the researchers determined that the effect of gender on bipolar disorder diagnosis in children and adolescents achieved only marginal significance.

Dr. Moreno’s group found little difference in the pharmacologic management of young and adult patients with bipolar disorder diagnosis in office-based practice. Both age-groups received a mood stabilizer in approximately two-thirds of the visits, with anticonvulsants prescribed most frequently in both groups. A similar proportion of children/adolescents and adults received a prescription for an antidepressant during their visits. No significant differences were observed in the proportions of visits for either age-group that included a prescription of antipsychotics, although atypical antipsychotics to treat bipolar disorder were prescribed more frequently to children and adolescents. Stimulants were prescribed approximately seven times more often in children/adolescent bipolar disorder visits than in adult bipolar disorder visits.

According to the investigators, these findings suggest that physicians may be basing treatment choices for child and adolescent bipolar disorder on prescribing practices for adult bipolar disorder. However, “the strength of treatment efficacy data differs markedly between adult and youth bipolar disorder,” the researchers commented. Although data supporting current adult prescription practices are well documented, efficacy data in pediatric bipolar disorder are lacking.

INTERPRETING THE FINDINGS

The cause of this rapid increase in bipolar disorder diagnoses among younger people is unclear, noted Dr. Moreno and colleagues. “Either bipolar disorder was historically underdiagnosed in children and adolescents and that problem has now been rectified, or bipolar disorder is currently being overdiagnosed in this age-group,” they reported.

Another possibility for this increased trend is an overlap in symptoms of ADHD and pediatric bipolar disorder, which may lead to diagnostic uncertainty, stated the investigators. “Some of the most frequently reported symptoms of pediatric bipolar disorder such as distractibility, pressured speech, and irritability overlap with ADHD symptoms.”

According to coauthor Mark Olfson, MD, MPH, of the New York State Psychiatric Institute of Columbia University in New York City, “We need to learn more about what criteria physicians in the community are actually using to diagnose bipolar disorder in children and adolescents and how physicians are arriving at decisions concerning clinical management. It would be interesting to test whether this increase in bipolar disorder diagnosis has also taken place outside the US.”

The researchers concluded that further studies are needed to determine the reliability and validity of different methods of diagnosing child and adolescent bipolar disorder in office-based practice, as well as to evaluate the effectiveness and safety of drugs commonly used to treat children and adolescents with bipolar disorder.       

—Karen L. Spittler

Suggested Reading
Moreno C, Laje G, Blanco C, et al. National trends in the outpatient diagnosis and treatment of bipolar disorder in youth. Arch Gen Psychiatry. 2007;64(9):1032-1039.

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