To the Editor: Recent studies from the United States and some European countries have assessed changes in the prevalence of antipsychotic medication use among children and adolescents over the past ten years (1,2,3). Concerns have been raised that these medications are prescribed for psychiatric disorders other than those for which they are intended. In Germany we were able to analyze administrative data from a regional health insurance fund that is responsible for insuring approximately one-third of the region's eligible population. The database, known as the Statutory Health Insurance Sample AOK Hesse/KV Hesse, contains information for a random sample of 1.9 million persons, or about 19% of all persons insured by the fund in this region.
We used data for children and adolescents between the ages of 0 and 19 years to compare prescription of antipsychotic drugs in 2000 (N=65,866) and in 2006 (N=56,169). We found that the prevalence of antipsychotic drug use increased from 1.9 per 1,000 to 2.8 per 1,000 over this period, which represents an increase of 50.6%. The increase resulted from a steep rise in prescription of second-generation antipsychotic drugs (mainly risperidone, olanzapine, and quetiapine). For second-generation antipsychotics, the prevalence increased from .4 per 1,000 in 2000 to 1.8 per 1,000 in 2006. Over the same period, first-generation antipsychotic drugs were prescribed less often, from 1.6 per 1,000 in 2000 to 1.4 per 1,000 in 2006—a decrease of 12%.
In the ten- to 14-year age group, a steep increase in second-generation antipsychotic prescribing could be observed, although the prevalence remained very low: from .1 per 1,000 in 2000 to 2.4 per 1,000 in 2006. In the 15- to 19-year age group, second-generation prescribing more than doubled—from 1.3 per 1,000 to 3.1 per 1,000. In both 2000 and 2006 a higher percentage of boys were prescribed second-generation antipsychotic drugs, and the prevalence increased more than fourfold (.6 per 1,000 to 2.7 per 1,000). A similar increase at a lower level was observed among girls (.2 per 1,000 to 1.0 per 1,000).
The database permitted us to determine the ICD-10 diagnoses that were entered in the quarter of the year in which the prescription was issued. When we restricted the analysis to the diagnosis coded by the physician who prescribed the antipsychotic drug, we found evidence of a shift from a diagnosis of schizophrenia in 2000 to diagnoses indicating behavioral problems in 2006. The ICD-10 diagnostic codes included F60–69 (disorders of adult personality and behavior), F70–79 (mental retardation), F80–89 (disorders of psychological development), and F90–98 (behavioral and emotional disorders with onset usually occurring in childhood and adolescence). A U.S. study by Domino and Swartz (1) found increased use of antipsychotics to treat affective disorders between 1996 and 2005. According to our data, there were no changes in antipsychotic prescribing for the treatment of affective disorders.
The increase in antipsychotic drug use among youths in Germany is considerably lower than increases in the United States (1) and the Netherlands (2), but it is higher than in the United Kingdom (3). When prevalence rates are compared, we have to keep in mind the methodological differences between studies as well as cultural and regional variations in prescribing habits. In contrast to the Netherlands study, which examined data for Dutch youths in eastern and northern parts of the country, our study was restricted to a single health insurance fund with a larger proportion of lower-income groups and to a single region—the federal state of Hesse. Differences in antipsychotic prescribing could also be attributable to differences in the socioeconomic status of the insured persons. In a nationwide German sickness fund that insured persons with higher incomes than those in our sample, the prevalence rate of antipsychotic prescribing in 2000 was higher than the rate found in our study (4).
At this time, the prevalence of treatment with antipsychotic drugs among youths is still low; however, the observed trend is similar to the steep increase in prescription of methylphenidate over the past ten years. The results of our study also raise concerns about the rise in off-label prescription of antipsychotics in Germany even though serious adverse drug events have been reported (5).
The authors thank I. Koester for data analysis.
Dr. Lehmkuhl is a member of the Eli Lilly Strattera Advisory Board. Dr. Schubert reports no competing interests.
Domino ME, Swartz MS: Who are the new users of antipsychotic medications? Psychiatric Services 59:507–514, 2008
Kalverdijk LJ, Tobi H, van den Berg PB, et al: Use of antipsychotic drugs among Dutch youths between 1997 and 2005. Psychiatric Services 59:554–560, 2008
Rani F, Murray ML, Byrne PJ, et al: Epidemiological features of antipsychotic prescribing to children and adolescents in primary care in the United Kingdom. Pediatrics 121:1002–1009, 2008
Zito JM, Safer DJ, de Jong-van den Berg LTW, et al: A three-country comparison of psychotropic medication prevalence in youth. Child and Adolescent Psychiatry and Mental Health 2:26, 2008. DOI:10.1186/1753-2000-2-26
Gardner DM, Baldessarini RJ, Waraich P: Modern antipsychotic drugs: a critical overview. Canadian Medical Association Journal 172:1703–1711, 2005