Mental disorder diagnoses among children and adolescents who use antipsychotic drugs.

Antipsychotic drugs are used increasingly by children and adolescents and there is concern about off-label use. We aimed to study which substances, and for which mental disorder diagnoses, antipsychotic drugs were prescribed to 0-18-year-old boys and girls in Norway. Linked data from the national health registry for prescription drugs in 2010 and mental disorder diagnoses in 2008-2012 were used to study the prevalence of antipsychotic drug use, the type of antipsychotic drug substances used, mental disorder diagnoses in users and distribution of drugs per diagnostic category across gender. In total, 0.18% of Norwegian children and adolescents were prescribed antipsychotic drugs during 2010, of which there were more boys (0.23%) than girls (0.13%). Risperidone was the most frequently used substance among boys (57.4%) and girls (32.3%), followed by aripiprazole (19.4%) in boys and quetiapine (27.4%) in girls. The most common mental disorder diagnoses among male users were hyperkinetic (49.9%) and autism spectrum disorder (27.1%), while anxiety disorders (41.5%) and depressive illness (33.6%) were most common among female users. A schizophrenia-like psychosis diagnosis was given to 11.1% of the male and 18.2% of the female users. A hyperkinetic disorder was diagnosed among 56.9% and 52.4% of the male risperidone and aripiprazole users, respectively. Among female quetiapine users, 57.1% were diagnosed with anxiety disorders and 52.4% with depressive illness. These results demonstrate that children and adolescents who use antipsychotic drugs are predominantly diagnosed with non-psychotic mental disorders such as hyperkinetic disorder among boys and anxiety disorder or depressive illness among girls.