Psychotropic drugs are frequently used in children and adolescents in France with a prescription rate of 2.5%. Antipsychotics (PA) and antidepressants (AD) each concern 0.3% of the pediatric population (Kovess et al., 2015). Despite appropriate pharmacological treatment, some patients are drug-resistant and have persisting symptoms and ineffective psychotropic treatments. These children and adolescents are generally exposed to many psychotropic molecules and often to poly-therapy. Additionally, hospitalizations for child psychiatry, sometimes of prolonged duration, are frequent for these patients. In France, to date, the psychiatrist practitioner rarely uses pharmacogenetic evaluation as a complementary tool for prescribing psychotropic drugs. Nevertheless, an individualized prescription taking into consideration the patient's individual metabolism could greatly improve the benefit and reduce the risk of psychotropic treatments in the pediatric population.