Related Experiment Video
Updated: Jun 25, 2026

Handwriting Analysis Indicates Spontaneous Dyskinesias in Neuroleptic Naïve Adolescents at High Risk for Psychosis
Published on: November 21, 2013
Olanzapine compared to quetiapine in adolescents with a first psychotic episode
Celso Arango1, Olalla Robles, Mara Parellada
1Psychiatry Department, Hospital General Universitario Gregorio Marañón, Centro de Investigación Biomédica en Red de Salud Mental, CIBERSAM, Madrid, Spain. carango@mce.hggm.es
Objective:
To compare the efficacy, safety, and tolerability of olanzapine and quetiapine in adolescents with first episode psychosis.
Method:
Fifty adolescents (age 16 +/- 1.25) with a first episode of psychosis were randomized to quetiapine or olanzapine in a 6-month open label study. Efficacy and side effect scales, as well as vital signs and laboratory data were recorded at baseline, 7, 15, 30, 90, and 180 days (end of study).
Results:
Out of the total sample included in the study, 32 patients completed the trial (quetiapine n = 16, olanzapine n = 16). Patients in both treatment groups had a significant reduction in all clinical scales with the exception of the negative scale of the Positive and Negative Symptom Scale (PANSS) for olanzapine and the general psychopathology scale of the PANSS for quetiapine. The only difference between treatment arms on the clinical scales was observed on the patients' strength and difficulties questionnaire (SDQ) scale, with greater improvement for olanzapine. Patients on olanzapine gained 15.5 kg and patients on quetiapine gained 5.5 kg.
Conclusion:
Olanzapine and quetiapine reduced psychotic symptoms in this adolescent sample. Patients on olanzapine gained significantly more weight. Side effects with both drugs seemed to be more prevalent than those reported in adult studies.
Related Concept Videos
Antipsychotic Drugs: Typical and Atypical Agents
Psychosis: Goals of Pharmacotherapy
Psychosis and Antipsychotic Drugs: Overview
Mania and Antimanic Drugs: Overview
Antidepressant Drugs: MAOIs and Other Agents
Antipsychotic Drugs: Therapeutic Uses and Side Effects
Despite these side effects, antipsychotics are used therapeutically for various purposes, including managing schizophrenia, preventing nausea and vomiting, curbing...