Clozapine Therapy Sample Collection - Method Comparison Study

Inclusion Criteria: * Study subjects must meet all the following criteria to be eligible for enrollment into the study: 1. Female or male subjects 21 years of age or older; 2. Current treatment with clozapine with documentation of diagnosed psychiatric condition requiring treatment; 3. Capable of understanding and complying with parameters as outlined in the protocol; 4. Capable of understanding and providing written informed consent, approved by an Institutional Review Board (IRB) prior to the initiation of any screening or study specific procedures. Exclusion Criteria: * 1\. Female or male subjects under the 21 years of age; 2. Unwilling or unable to follow protocol requirements or to give written informed consent.