The only drug approved for pervasive developmental disorders (PDD) in Japan is pimozide. Several psychotropic drugs are also prescribed for offlabel use in Japan, but details regarding their prescription and use are largely unknown. The purpose of this study was to clarify the use of drug treatment in Japanese children with PDD.

Data were extracted from claims data from the Japan Medical Data Center for children younger than 18 years of age who were newly diagnosed with PDD (International Classification of Diseases version 10 codes: F84) from 2005 to 2010 (total of 3276 patients as of 2010). The prescription rates were presented as the percentage of PDD patients who were prescribed each drug.

Prior to 2010, the prescription rates for atypical antipsychotics, other antipsychotics, psychostimulants, all other central nervous system drugs, anticovnvulsants, non-barbiturates, and Parkinson’s disease/syndrome drugs significantly increased among the Anatomical Therapeutic Chemical classifications defined as the “nervous system” (trend P≤0.02). The prescription rate for risperidone consistently increased, reaching 6.9% in 2010 (trend P<0.0001), the highest rate of the surveyed drugs among the antipsychotics. The prescription rate for aripiprazole also increased (trend P<0.0001), reaching 1.9% in 2010. The prescription rate for pimozide showed no annual changes, with a low rate of 0.4% in 2010.

Compared with pimozide, the prescription rates for risperidone, aripiprazole and other psychotropic drugs have increased. Because safety data for these drugs in Japanese children are sparse, there is a need for future safety evaluations of these drugs in Japanese children.