The neuropsychiatric symptoms of schizophrenia will be assessed using the 30-item PANSS, which provides a total score (sum of the scores of all 30 items) and scores for 3 subscales, the positive subscale (7 items), the negative subscale (7 items), and the general psychopathology subscale (16 items). Each question is rated on a scale of 1 (absent) to 7 (extreme).

The PANSS is a 30-item scale designed to assess various symptoms of schizophrenia including delusions, grandiosity, blunted affect, poor attention, and poor impulse control. The 30 symptoms are rated on a 7-point scale that ranges from 1 (absent) to 7 (extreme psychopathology). The PANSS total score consists of the sum of all 30 PANSS items and ranges from 30 to 210, higher scores indicate worsening.

Number of days from baseline (day 1 of core phase) to relapse as evaluated according the Csernansky criteria. A patient was considered to have relapsed if they met one or more of the following criteria: (1) psychiatric hospitalization; (2) an increase in the level of psychiatric care and an increase of 25 percent (%) from baseline in the Positive And Negative Syndrome Score (PANSS) total score (or an increase of 10 points if the baseline score was 40 or less); (3) deliberate self-injury; (4) suicidal or homicidal ideation that was clinically significant in the investigator's judgment; (5) violent behavior resulting in clinically significant injury to another person or property damage; (6) substantial clinical deterioration, defined as a change score of 6 ("much worse") or 7 ("very much worse") on the Clinical Global Impressions Scale (CGI-C); and/or (7) the required dose of the antipsychotic exceeds the maximum approved dose.

Number of participants with a relapse event with relapses evaluated according the Csernansky criteria. A patient was considered to have relapsed if they met one or more of the following criteria: (1) psychiatric hospitalization; (2) an increase in the level of psychiatric care and an increase of 25% from baseline in the PANSS total score (or an increase of 10 points if the baseline score was 40 or less); (3) deliberate self-injury; (4) suicidal or homicidal ideation that was clinically significant in the investigator's judgment; (5) violent behavior resulting in clinically significant injury to another person or property damage; (6) substantial clinical deterioration, defined as a change score of 6 ("much worse") or 7 ("very much worse") on the Clinical Global Impressions Scale (CGI-C); and/or (7) the required dose of the antipsychotic exceeds the maximum approved dose.

The pre-dose plasma concentration (Cpredose) at Day 8 is defined as the plasma concentration obtained before a dose is given on Day 8. The mean Cpredose at Day 8 was measured in nanogram per milliliter (ng/ml).

The Cpredose at Day 36 is defined as the plasma concentration obtained before a dose is given on Day 36. The mean Cpredose at Day 36 was measured in ng/ml.

The Cpredose at Day 64 is defined as the plasma paliperidone concentration obtained before a dose is given on Day 64. The mean Cpredose at Day 64 was measured in ng/ml.

The Cpredose at Day 92 is defined as the plasma paliperidone concentration obtained after the treatment interval of the study drug (that is 4 weeks) passed after the final dose (Day 92). The mean Cpredose at Day 92 was measured in ng/ml.

The Cmax is defined as maximum observed analyte concentration.

The Tmax is defined as actual sampling time to reach maximum observed analyte concentration.

The AUCtau is a measure of the plasma paliperidone concentration from time zero to end of dosing interval. It is used to characterize drug absorption.

The Css av is defined as value of average analyte concentration at steady-state (after 4 Intramuscular Injections of Paliperidone Palmitate).

Plasma decay half-life is the time measured for the plasma concentration to decrease by one half.

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The DIEPSS is a scale used to evaluate the severity of drug induced extra-pyramidal symptoms occurring during antipsychotic drug treatment. Scale consists of 8 individual symptom scales with scores ranging from 0 (none/normal) to 4 (severe). The total score is the average of the 8 item scores, for a total range of 0 (normal) to 4 (severe). Overall severity was assessed at 5 levels (0 \[none, normal\]; 1 \[Very Mild\]; 2 \[Mild\]; 3 \[Moderate\]; 4 \[severe\]).

The Plasma Concentration (Cmax) is defined as maximum observed analyte concentration.

The Tmax is defined as actual sampling time to reach maximum observed analyte concentration.

The Area Under the Curve From Time Zero to End of Dosing Interval (AUCtau) is a measure of the plasma paliperidone concentration from time zero to end of dosing interval. It is used to characterize drug absorption.