An Open-Label Trial of Memantine for Cognitive Impairment in Patients With Post-Traumatic Stress Disorder

1. Patients, men and women between 18 and 65 years of age, inclusive.
2. Patients with diagnosis of Posttraumatic Stress Disorder (309.81) for at least 6 months, as determined by the Structured Clinical Interview for DSM-IV Axis 1 Disorders (SCID).
3. Patients with a score of at least 1 standard deviation below the mean on the Spatial Span, Logical Memory I and Letter-Number Sequencing subtest's of the Wechsler Memory Scale III (Third edition).
4. Patients, who are able to comprehend and satisfactorily comply with protocol requirements and have an ability to read and write English,
5. Patients, who signed the written informed consent given prior to entering any study procedure.
6. Patients must be clinically stable on their medications for past three months

Exclusion Criteria:

1. Patients with a concurrent DSM-IV Axis I or Axis II diagnosis in any of the following categories:

   • 1.1. Delirium, Dementia, Amnestic and other Cognitive disorders
   • 1.2. Mental Retardation
   • 1.3. Lifetime Schizophrenia and other Psychotic Disorders
   • 1.4. Lifetime Bipolar I Disorder
   • 1.5. Alcohol or Substance Dependence or Abuse (excluding nicotine) in one month prior to the Screening Visit
   • 1.6. Any other concurrent Axis I Disorder (including Major Depressive Disorder) must be secondary to the primary diagnosis of PTSD.
2. Patients with a score of less than 1 standard deviation below the mean on the Spatial Span, Logical Memory I and Letter-Number Sequencing subtest's of the Wechsler Memory Scale III at the screening visit.
3. Patients with a history of treatment with cholinesterase inhibitor drugs like donezepil, galantamine or rivigstamine.
4. Patients with a history of intolerance or hypersensitivity to memantine.
5. Patients with a history of seizures and traumatic head injury.
6. Patients requiring concomitant treatment amantadine or dextromethorphan or carbonic anhydrase inhibitors.
7. Patients who based on history or mental status examination have a significant risk of committing suicide.
8. Patients who are homicidal or violent and who are in the Investigator's opinion in significant imminent risk of hurting others.
9. Patients with a positive urine drug screen, for drugs of abuse.
10. Patients who have participated in any clinical trial within one month prior to the Screening Visit, or in a clinical trial involving a psychotropic medication within the 3 months prior to the Screening Visit.
11. Patients who have a medical condition that, in the Investigator's opinion, would expose them to an increased risk of a significant adverse event or interfere with assessments of safety and efficacy during the course of the trial.
12. Patients with any current malignancy, or any clinically significant hematological, endocrine, cardiovascular, renal, hepatic, gastrointestinal or neurological disease (including any form of epilepsy). If there is a history of such disease but the condition has been stable for at least the past year and is judged by the investigator not to interfere with the patient's participation in the study, the patient may be included.
13. Patients whose laboratory values at the Screening visit will be 2 times greater than ULN.
14. Patients who require concomitant therapy with any prohibited prescription or over-the-counter medication.
15. Patients who are unable to speak, read, and understand English or are judged by the investigator to be unable or unlikely to follow the study protocol and complete all scheduled visits.
16. Women patients who are pregnant, planning to become pregnant, or if of childbearing potential, not using an acceptable method of birth control.