This study is being done to look at the electrical activity of the heart. This study will help decide whether taking recordings for a 24-hour period gives more useful information than recording it for a few seconds in a doctor's office. The study will compare 24 hour electrocardiogram (ECG) results of patients taking thioridazine (Mellaril) to those of other patients taking different medications that took part in another study.

The objective of the study is to assess the Tpe and QTc measures in 24 hr Holter echocardiograms in patients treated with atypical antipsychotic drgs (APDs). The primary comparisons of interest are olanzapine (no QTc prolongation) to ziprasidone (QTc prolongation) and thioridazine (QTc prolongation) as well as ziprasidone (possibly low TdP risk) to thioridazine (TdP risk). Secondary comparisons will be among all APDs available. In a previously approved study, conventional 24 hr Holter electrocardiograms were recorded from a total of 78 subjects during the course of treatment with psychotropic medications and without medication (in the case of normals and unmedicated patients). These recordings will be analyzed to yield Tpe, QTc and heart rate, and other measures. Data from additional patients is needed, therefore this study will include only patients currently treated with Mellaril (thioridazine), Risperdal (risperidone) and Seroquel (quetiapine).

Inclusion Criteria:

• Patients must be male or female, age 18-65

  • Patients must have a definitive diagnosis by DSM-IV criteria of schizophrenia, bipolar or schizoaffective disorder.
  • Patients can be receiving inpatient or outpatient treatment at time of enrollment.
  • Patients must have been treated with (Mellaril) thioridazine, (Risperdal) risperidone or (Seroquel) quetiapine at least three months at time of enrollment.
  • Patients must be able to provide written informed consent

Exclusion Criteria:

• Patients with a primary diagnosis other than schizophrenia, schizoaffective or bipolar disorder

  • Patients who are currently taking other medications that have been shown to prolong the QTC, including tricyclic antidepressants, fluoroquinolones or antiarrythmics.
  • Patients unable to provide written informed consent.

Adults diagnosed wtih schizophrenia, bipolar or schizoaffective disorder