A Retrospective Investigation of Clozapine Treatment in Autistic and Nonautistic Children and Adolescents in an Inpatient Clinic in Turkey.

Objective: The aim of this retrospective study is to examine the clinical outcomes and safety of clozapine in children and adolescents with schizophrenia or other psychotic disorders/autism spectrum disorder (ASD) or affective disorders.

Methods: The inpatient and outpatient files of all children and adolescents treated with clozapine over a period of 34 months (from October 2011 to July 2014) were reviewed. Demographic and clinical data were examined to describe clinical and metabolic findings, dosing, and tolerability of clozapine treatment in youth with schizophrenia, other psychotic disorders, ASD, or bipolar disorder.

Results: The 37 pediatric patients included 26 patients with schizophrenia or other psychotic disorders, 7 patients with ASD complicated by schizophrenia or other psychotic disorders or affective disorders, and 4 patients with ASD only. In all groups (n = 37) there was a significant reduction (p < 0.001) in Brief Psychiatric Rating Scale (BPRS) points after clozapine treatment during the inpatient period (38.78 ± 27.75 days). In patients with schizophrenia or other psychotic disorders co-occurring with ASD or not (n = 31), there was a significant improvement in psychotic symptoms according to Positive and Negative Syndrome Scale (PANSS) total scores and subscores (p < 0.001). Of the 26 patients with schizophrenia or other psychotic disorders, 8 (30.8%) showed a positive response (>30% symptom reduction on BPRS). In patients with ASD complicated by schizophrenia or other psychotic disorders or bipolar disorders (n = 7), there was a significant reduction (p = 0.017) in BPRS scores after clozapine treatment. The discontinuation rate for clozapine was 10.8%, and the most frequently observed side effect was hypersalivation (54.1%). Neutropenia associated with clozapine was observed in only one patient (2.7%).

Conclusions: Clozapine seems to be effective and safe in children and adolescents with schizophrenia or other psychotic disorders co-occuring with ASD or not. There is a need for further studies for determining the efficacy of clozapine in children and adolescents with bipolar affective disorder or ASD.