Predicting Responses to PTSD Treatment With Iris and Cardiovascular Tests

Inclusion Criteria:

• Veteran of the U.S. Armed Forces

• Current diagnosis of PTSD (as documented in clinical chart and/or per participantreport; a rule out diagnosis from a VA provider accompanied by a referral to the VAPTSD Outpatient Clinic (POC) will also be considered sufficient for inclusion)

• Woman of childbearing potential must agree to abstain from sexual relations thatcould result in pregnancy or use an effective method of birth control acceptable toboth participant and study clinician during the study. Men are not required to usecontraception during the study.

Exclusion Criteria:

• Psychiatric:

• Any known diagnosis of a primary psychotic or major neurocognitive disorder,including schizophrenia, brief psychotic disorder, or Alzheimer's or otherdementia, as well as bipolar type I

• Severe psychiatric instability or severe situational life crises, includingevidence of being actively suicidal or homicidal, or any behavior which posesan immediate danger to participant or others.

• Note: Nonsuicidal depression comorbid with PTSD will not be exclusionary.Participants may continue in any concurrent psychotherapy orpharmacotherapy in which they are participating, other thanpharmacotherapeutic agents specifically listed above. Participants withactive suicidal ideation or with depression severe enough to requirepsychiatric hospitalization will be excluded.

• Medical:

• Significant bilateral visual loss (would preclude performing the PLRmeasurements)

• Current pregnancy or lactation

• Allergy or previous adverse reaction to prazosin or other alpha-1 antagonist

• Acute or unstable chronic medical illness, including unstable angina, recentmyocardial infarction (within 6 months), congestive heart failure, preexistinghypotension (systolic <110) or orthostatic hypotension (systolic drop > 20mmHgafter two minutes standing or any drop accompanied by dizziness); autoimmunedisorders; insulin-dependent diabetes

• Chronic renal or hepatic failure, acute pancreatitis, Meniere's disease, benignpositional vertigo, or narcolepsy

• Medication / treatment:

• Any use within the 7 days prior to baseline of prazosin, doxazosin, clonidine,guanfacine, trazodone, or nonbenzodiazepine hypnotics, and/or unwillingness toavoid these medications for the duration of the study

• Use of avanafil (Stendra), sildenafil (Viagra), tadalafil (Cialis), andvardenafil (Levitra) will be not be permitted during the study dose titrationperiod because of increased risk of hypotension in combination with alpha-1blockers, but will be allowed at 1/2 the usual starting dose following dosetitration

• Current use of nitrates, or of alternative medications or supplements withsignificant vasodilatory properties (e.g., nitrate containing supplements)Participants may also be excluded at the discretion of PI or study cliniciansif they appear to be unsuitable for this research study for a reason notdetailed here.