Safety and Efficacy of Cannabidiol (CBD) for Symptoms of PTSD in Adults

Inclusion Criteria All Participants * Ability and willingness to provide informed consent * Stated willingness to comply with all study procedures and availability for duration of the study * Aged 21-65 years * Able to read and communicate in English * Tetrahydrocannabinol (THC) use less than 3 days per week PTSD Participants * Meets Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) diagnostic criteria for a current diagnosis of Post-Traumatic Stress Disorder (PTSD) on the Mini-Mental State examination (MMS), with symptoms present for at least 1 month * Clinician administered Clinical Assessment of Pragmatics (CAPs) score ≥27 at study enrollment and start of Cannabidiol (CBD) observation * Stable psychopharmacologic and/or psychotherapeutic intervention for 4 weeks prior to enrollment Exclusion Criteria All Participants * Current use of prescribed or commercially available CBD products, including Epidiolex® * Suicidal ideation (as defined by answer of "yes" to item 4 or 5 on the baseline Columbia Suicide Severity Rating Scale (C-SSRS) or attempt within 6 months prior to enrollment) * Cognitive impairment in the clinical judgment of the investigator that would impact ability to complete study assessments or confound study results (e.g., neurodegenerative condition or other) * Meets criteria for substance or alcohol use disorder of moderate or greater severity within 6 months prior to study enrollment based on the Mini-Mental State examination (MMS); nicotine dependence permitted * Self-reported cannabis use on \> 3 days/week starting 4 weeks prior to enrollment * Positive urine drug screen for illicit substances other than cannabis * Pregnant \[confirmed by serum human chorionic gonadotropin (hCG) test\], or breastfeeding * Co-morbid medical conditions or concomitant treatments that may adversely impact ability to participate in the trial in the clinical judgment of the investigator \[e.g., significant immunosuppression due to active chemotherapy, recent organ transplant, uncontrolled diabetes, glomerular filtration rate (GFR) \< 25ml/min or on dialysis, recent acute myocardial infarction (MI), Class IV heart failure, or taking any high-risk drugs for drug-drug interactions\] * Treatment with another investigational drug or other intervention within 3 months prior to enrollment * History of psychosis (schizophrenia, schizophreniform disorder, schizoaffective disorder, or substance induced psychosis), active bipolar disorder, or borderline personality disorder diagnosed by a mental health professional * History of open head injury * Self-report of exposure to trauma within 30 days prior to enrollment * Active military service in the 30 days prior to enrollment * Inpatient psychiatric hospitalization within 6 months prior to enrollment * Seizure in the last 6 months * Use of concomitant anti-viral human immunodeficiency virus (HIV) medications (PrEP permitted) Control Participants * History of diagnosed PTSD * Pregnant (self-reported) or breastfeeding Participants who consent to functional magnetic resonance imaging (fMRI) procedures * Claustrophobia, pregnancy, or any condition (e.g., significant hearing difficulties) that would preclude MRI scanning, in the clinical judgment of the investigator * Presence of metal objects in or on the body (e.g., pacemakers, aneurysm clips, metallic prostheses, bone plates, braces, orthodontic devices, cochlear implants/hearing aids, non-removable piercings/implants or metallic-ink tattoos, or shrapnel fragments) * Other confounding medical conditions (e.g., Tourette's or Tic Disorder) that would preclude MRI scanning, in the clinical judgement of the investigator PTSD Participants * Index trauma before age 18 and no other traumatic experiences which could relate/identify as part of PTSD * History of allergic reaction or significant adverse events (AE) related to cannabis, CBD, or THC * Currently involved in events giving rise to PTSD * Alanine transaminase (ALT)/Aspartate transaminase (AST)/Bilirubin \> 2 x upper limit of normal (ULN) at screening (abnormalities on the comprehensive metabolic panel or complete blood count deemed to be of clinical significance in the judgement of the investigator and clinical team will be evaluated in the clinical context of the participant's history and physical examination to determine eligibility and testing may be repeated if clinically appropriate at the discretion of the investigator) * Refusal to use at least one form of birth control throughout study participation \[including, but are not limited to, male or female condoms, diaphragm, or cervical cap (all with or without spermicide) abstinence, or hormonal/implanted birth control, e.g., pill, injection, intra-uterine device (IUD), implant\] by participants who can become pregnant