Datapoints: Antipsychotic Prescribing Trends Among Youths, 1997-2002

Prescriptions for antipsychotics grew markedly from 1997 to 2002 because of the increased use of second-generation antipsychotics (1), but little is known about recent trends in the use of antipsychotics among youths. Although there is a paucity of recent national data on antipsychotics among youths, there are indications that the use of antipsychotics is on the rise in this population (2).

To explore whether antipsychotic prescribing is increasing for youths, we examined prescription data from the National Ambulatory Medical Care Surveys (NAMCSs) from the periods 1997 through 1998, 1999 through 2000, and 2001 through 2002 (3). The NAMCS is an annual probability sample survey of in-person visits to physician offices in the United States. As described elsewhere (1), our analysis involved 11 first-generation agents (chlorpromazine, fluphenazine, haloperidol, loxapine, mesoridazine, molindone, perphenazine, promazine, thioridazine, thiothixene, and trifluoperazine) and six second-generation agents (aripiprazole, clozapine, olanzapine, quetiapine, risperidone, and ziprasidone) prescribed for patients younger than 20 years.

Weighted visit estimates involving antipsychotics were calculated on the basis of the inflation factor called patient sampling weight. The weighted samples of visits involving antipsychotics were .66 million in 1997 through 1998, 1.59 million in 1999 through 2000, and 2.19 million in 2001 through 2002. Visit rate, expressed as number of visits per 1,000 persons younger than 20 years, was also computed to account for changes in the population. During the study period these visit rates more than tripled, from 4.26 in 1997 through 1998 to 13.57 in 2001 through 2002 (95 percent confidence interval [CI]=2.06 to 6.47 and CI=7.33 to 19.80, respectively, p<.01).

As shown in Figure 1, the increase in antipsychotic prescribing for youths was driven primarily by the use of second-generation agents. The number of visits for second-generation agents nearly quadrupled during the study period: .51 million in 1997 through 1998 to 2.01 million in 2001 through 2002 (CI=.23 to .80 and CI=1.04 to 2.99, respectively, p<.01). During the six-year study period second-generation agents were prescribed in 83.16 percent of the visits that involved antipsychotics. The most frequently prescribed second-generation agents were risperidone and olanzapine. Overall, psychiatrists were involved in most (86.5 percent) of these visits; no significant trend was found in antipsychotic prescribing practices by specialty.

Our results show a significant increase in antipsychotic prescribing for youths, mainly because of the growing use of second-generation agents. This finding could be partly explained by the use of second-generation antipsychotics among youths for nonpsychotic disorders (4). Definitive safety and efficacy data are urgently needed to support burgeoning and off-label use of second-generation antipsychotics among youths.

Dr. Aparasu is affiliated with the department of clinical pharmacy at the South Dakota State University College of Pharmacy, Box 2202 C, 1 Administration Lane, Brookings, South Dakota 57007 (e-mail, [email protected]). Dr. Bhatara is with the University of South Dakota School of Medicine in Sioux Falls. Harold Alan Pincus, M.D., and Terri L. Tanielian, M.A., are editors of this column.