Community treatment orders (CTOs) are a form of compulsory treatment of individuals with a mental illness in the community. The objectives of this study were to determine the demographic, clinical, and treatment plan factors associated with antipsychotic polypharmacy and high-dose antipsychotics among individuals issued with a CTO. This was a secondary analysis of all 377 individuals who were prescribed an antipsychotic, extracted from a retrospective study of 378 individuals issued with a CTO by the New South Wales Mental Health Review Tribunal in Australia in 2009. Deidentified information relating to individuals treatment plans, demographic, and clinical details were systematically extracted. Of the 377 individuals, 121 (32 ) were prescribed antipsychotic polypharmacy and 101 (27 ) high-dose antipsychotics. Unadjusted and adjusted odds ratios (ORs) and 95 confidence intervals (95 CIs) for factors associated with antipsychotic polypharmacy and high-dose antipsychotics were computed using binary logistic regression. There was a strong association between the use of antipsychotic polypharmacy and high-dose antipsychotics (P <0.001). Only treatment plan factors were associated with antipsychotic polypharmacy and high-dose antipsychotics in adjusted models. Although first-generation long-acting injectable antipsychotics and clozapine were associated with antipsychotic polypharmacy (adjusted OR, 9.12; 95 CI, 4.21-19.74; adjusted OR, 7.97; 95 CI, 2.93-21.72), oral second-generation antipsychotics and risperidone long-acting injection were associated with high-dose antipsychotics (adjusted OR, 5.67; 95 CI, 2.89-11.12; adjusted OR, 8.14; 95 CI, 3.22-20.53). Therefore, the use of antipsychotic polypharmacy and high-dose antipsychotics among individuals issued with CTOs is associated only with the drugs prescribed in their treatment plans and not their individual demographic and clinical characteristics.