The VA Biorepository Brain Bank (VABBB) National Posttraumatic Stress Disorder Brain Bank (PTSD Brain Bank) seeks to support research on the causes, progression and treatment of PTSD affecting Veterans. The PTSD Brain Bank is able to carry out this important work by obtaining brain and spinal cord tissue samples from Veterans and non-Veterans who have or have not been diagnosed with PTSD or Major Depressive Disorder. If you would like to learn more about how to get involved with this study, please refer to the VABBB Brochure or the study website. To enroll in the study, you may complete the Permission to Contact Form.