Effects of Escitalopram on Autonomic Reactivity in Post Traumatic Stress Disorder

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.