Please select the eligibility criteria that correspond to the clinical trial below.
Title: Antipsychotic Polypharmacy in Schizophrenia
Brief Summary: The literature suggests that when a patient is prescribed more than one antipsychotic for at least 30 days, he or she is likely to continue on that combination. In this 12 week study 100 adult patients being treated on more than one antipsychotic medication for at least 30 days will be recruited. In order to control for the natural course of the illness, patients will be randomly assigned to one of two groups: the first group will continue the second medication hidden in a capsule at the same dose, while the second group will be given an inactive capsule (placebo) - the capsules in both group will be identical such that neither the patient nor the treating doctor will be able to identify the group assignment.


Options:
A: Inclusion Criteria:

* Subjects treated with clozapine for the indication of poor response to other antipsychotic medications.
* Treatment with clozapine is at a stable dose for at least 12 weeks. Dose must be 400 mg/day or more, unless side effects limited increase of dose.

Exclusion Criteria:

* Subjects with significant alcohol or substance abuse in the past 3 months.
* Subjects with a previous trial of risperidone augmentation of clozapine
* Subjects who are pregnant, breast-feeding, or women of child-bearing potential not using adequate contraception
* Subjects requiring treatment with anticonvulsants.
* Subjects with known hypersensitivity or allergy to risperidone.
* Subjects with hematological or other contraindications to continued clozapine treatment.
B: Inclusion Criteria:

* schizophrenia
* CGI \>=4
* washout of antipsychotics at least 3-5 days
* written informed consents

Exclusion Criteria:

* History of serious adverse events to sulpiride or amisulpride
* History of neuroleptic malignant syndrome or tardive dyskinesia to antipsychotics
* treatment-resistant schizophrenia
* long-acting antipsychotics in the past 3 months
* comorbid with substance abuse/dependence
* female subjects with pregnancy
* severe physical illness
C: Inclusion Criteria:

* Male or female subjects aged ≥ 18 years
* Suffering from a primary psychotic disorder (confirmed using the MINI International Neuropsychiatric Interview for DSM-IV (Version 5.0.0)
* Treated with two antipsychotic drugs for at least 30 days (excluding "prn" or "as needed" antipsychotic prescriptions)

Exclusion Criteria:

* A history of treatment with a depot antipsychotic within 6-months of enrollment will be excluded form the study unless the depot antipsychotic is considered the "main" antipsychotic drug in this study
D: Inclusion Criteria:

* Patients diagnosed with schizophrenia or schizoaffective disorder
* stable with respect to disease symptoms and other medical conditions
* stable on any oral antipsychotic drug (except clozapine) for 4 weeks before the study
* patients identify a relative or acquaintance who can complete a questionnaire with additional information about the patient
* if female, using birth control.

Exclusion Criteria:

* Patient is not eligible if currently hospitalized, or was treated for an acute disease-related crisis within the past 4 weeks
* at risk to self or others
* use of injectable antipsychotic drugs or electroconvulsive therapy within past 6 months, or currently using carbamazepineor an oral antipsychotic drug in a dose that is higher than 8 milligrams per day in risperidone equivalents, of long-acting risperidone in an earlier study, of clozapine, or use of investigational drugs within 30 days, or of electroconvulsive therapy within past 6 months
* presence of liver or kidney damage
* history of neuroleptic malignant syndrome
* if pregnant or breast-feeding
* not using birth control
* abusing drugs or alcohol.

Answer: C