The study looked at relationship between escitalopram and heart rate variability and QT variability in veterans with PTSD.

The investigators are studying if taking escitalopram will normalize heart rate variability and a decrease (or no effect implying a lack of serious cardiac side effects) including QT variability in veterans with PTSD.

Inclusion Criteria:

• Inclusion Criteria - Group I
• Patients, men and women between 19 and 55 years of age, inclusive.
• Patients with diagnosis of Posttraumatic Stress Disorder as determined by Mini-International Neuropsychiatric Interview (M.I.N.I.).
• Patients, who are able to comprehend and satisfactorily comply with protocol requirements and have an ability to read and write English.
• Patients, who signed the written informed consent given prior to entering any study procedure.
• Inclusion Criteria - Group II
• Patients, men and women between 19 and 55 years of age, inclusive.
• Patients with diagnosis of Major Depression as determined by Mini-International Neuropsychiatric Interview (M.I.N.I.). A diagnosis of PTSD will be exclusionary.
• Patients, who are able to comprehend and satisfactorily comply with protocol requirements and have an ability to read and write English.
• Patients, who signed the written informed consent given prior to entering any study procedure.

Exclusion Criteria:

• History of cardiovascular disease or a history of hypertension.
• Patients with a concurrent Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnosis in any of the following categories as determined by the M.I.N.I.
• Lifetime Schizophrenia and Schizoaffective Disorder
• Lifetime Bipolar I Disorder
• Substance Dependence or Abuse (excluding nicotine) within one month prior to the Screening Visit.
• Patients with a history of intolerance or hypersensitivity to escitalopram or citalopram.
• Patients who based on history or mental status examination have a significant risk of committing suicide. Current suicide risk (past month) will be assessed using the M.I.N.I. Suicidality Module. Subjects considered at high suicide risk based on the module (> 17 points) will be excluded from study participation.
• Patients who are homicidal or violent and who are in the Investigator's opinion in significant imminent risk of hurting others.
• Subjects will be excluded who have a history of significant medical illness and who are on medications that affect cardiac and/or autonomic function.
• Female patients who are pregnant, planning to become pregnant, or if of childbearing potential, not using an acceptable method of birth control.

12 weeks

Due to small number of subjects recruited in major depression group we are unable to compare to the PTSD group.