The primary objective of this single-center multi-site retrospective chart review is to determine if paliperidone palmitate and/or risperidone long-acting injection can decrease the number of psychiatric relapses following their initiation in an inpatient acute psychiatric unit compared to oral antipsychotic therapy and determine if one treatment is superior to the other in this regard. This study will utilize a mirror-image design and incorporate up to a 3 years of follow-up following the index admission. Secondary objectives of this study will be to determine the change in hospital resource utilization for psychiatric reasons following treatment initiation, and to determine the difference in time to relapse.

Inclusion Criteria:

• Patients who were initiated on either Risperidone long-acting injection or Paliperidone palmitate during an acute psychiatric admission for schizophrenia or other psychotic related disorders.

Exclusion Criteria:

• Patients who had their long-acting injection stopped prior to the discharge date of their index admission.
• Patients who received a long-acting injection in the year prior to the index admission.
• Patients who had a psychiatric admission to a forensic, rehabilitation or high dependency unit during the observation period prior to or following their index admission.

Patients initiated on long-acting injectable anipsychotics from the regional hospitals under the direction of the Vitalité health network.