An Efficacy and Safety Study of Extended-Release (ER) Paliperidone in Adolescent Participants With Schizophrenia

The purpose of this study is to evaluate the efficacy and safety of extended-release (ER) paliperidone compared to aripiprazole (atypical antipsychotic) in symptomatic (having symptoms) adolescent participants with schizophrenia (psychiatric disorder with symptoms of emotional instability, detachment from reality, often with delusions and hallucinations \[imagining things\], and withdrawal into the self) .

This is a multi-center (conducted in more than 1 center), double-blind (neither physician nor participant knows the name of the assigned drug), randomized (study drug is assigned by chance), active-controlled (paliperidone ER is compared to aripiprazole), parallel-group (a medical research study comparing the response in 2 or more groups of participants receiving different treatments), flexible-dose (the physician has the freedom to give different doses to the participant depending on how they respond to treatment) study designed to determine the efficacy and safety of paliperidone ER in symptomatic adolescents (12 to 17 years of age) with schizophrenia. The total duration of the study will be approximately 29 weeks. The study consists of 3 phases: a Screening phase up to 3 weeks (with a possible overlapping washout period), a Double-blind acute phase of 8 weeks, and a Double-blind maintenance phase of 18 weeks. Participants will be randomly assigned to 1 of the 2 treatment groups (paliperidone ER or aripiprazole flexible oral doses). Dosage will be adjusted at the scheduled visits. Efficacy of the participants will primarily be evaluated through Positive and Negative Syndromes Scale (PANSS). Participants' safety will be monitored throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Participants must currently meet the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) criteria for schizophrenia and have experienced symptoms of the illness for at least 1 year, and they should have had at least treatment with 1 antipsychotic before participation in this study
* Participants having a Positive and Negative Syndromes Scale (PANSS) score between 60 and 120 inclusive at Screening
* Female participants must be incapable of pregnancy, or if heterosexually active and capable of pregnancy, have been using an acceptable method of contraception for at least 1 month before study entry and agree to continue use contraception methods for the duration of the study, or if sexually abstinent (not having sexual intercourse) and capable of pregnancy, must agree to continue abstinence or to use an acceptable method of birth control
* Participants must not be a danger to themselves or others, and must have family support available to be maintained as out-patients
* Participants with a weight of equal to or greater than 29 kilogram

Exclusion Criteria:

* Participants with mild (not serious), moderate (medium level of seriousness), or severe (very serious, life threatening) mental retardation
* Participants with a known or suspected history of substance dependence (including alcohol, but excluding nicotine or caffeine) as per the DSM-IV criteria in the 3 months before Screening
* Participants with a history of certain neurological (pertaining to the nervous system) disorders or insulin-dependent diabetes mellitus (disorder in which there is decreased insulin in the body or the body's insulin is not effective, resulting in high blood sugar, increased thirst and urine, and many other side effects)
* Participants who have received a depot injectable antipsychotic within 2 treatment cycles before the Screening visit
* Participants who have received clozapine in 2 months before the Baseline visit (Day 1 of Week 1)