Inclusion Criteria:  Established diagnosis of Post-Traumatic Stress Disorder (PTSD) corresponding to Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria Time since index event according to Life Events Checklist / Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) Criterion A at least 3 months before screening visit PTSD must be the clinically pre-dominant disorder, as per investigator´s judgement. Other comorbid psychiatric disorders are allowed, unless specifically excluded in the exclusion criteria A total severity score of ≥ 33 on the PTSD Checklist for DSM-5 (PCL-5) at the screening visit Moderate to severe PTSD confirmed by CAPS-5 range ≥ 30 confirmed at screening visit Male or female patients, 18 to 65 years of age, both inclusively at the time of informed consent Women who are of child-bearing potential (WOCBP) must be able and willing to use two methods of contraception which include one highly effective method of birth control per International Council on Harmonisation (ICH) M3 (R2) that result in a low failure rate of less than 1%, plus one additional barrier method Signed and dated written informed consent in accordance with International Council on Harmonisation - Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial  Exclusion Criteria:  Corresponding to DSM-5, had ever met diagnostic criteria for schizophrenia, schizoaffective disorder, schizophreniform disorder, bipolar disorder, delusional disorder, brief psychotic disorder or any other psychotic disorder as well as Major Depressive Disorder (MDD) with psychotic features as assessed by the Mini-International Neuropsychiatric Interview (MINI) at the time of screening Any psychiatric or non-psychiatric medical condition likely to negatively impact trial participation as per the judgement of the investigator Acute stress disorder or significant traumatic event within 3 months prior to the screening visit Use of stimulant medications within 3 months prior to the screening visit (Attention Deficit Hyperactivity Disorder (ADHD) diagnosis alone is not exclusionary) Severe traumatic brain injury (life-time) or moderate traumatic brain injury within the last 2 years prior to screening visit or 3 months for mild traumatic brain injury, based on the Ohio State University Traumatic Brain Injury (TBI) Identification Method Short Form. Or history of traumatic brain injury that would impact ability to complete trial assessments or procedures according to investigator. Current treatment with trauma focused therapy (i.e. Cognitive Processing Therapy (CPT), Prolonged Exposure Therapy (PE), Eye Movement Desensitization and Reprocessing (EMDR)). A psychotherapy in type, intensity and/or frequency other than trauma focused therapy is allowed if stable within the last 8 weeks prior to screening and not anticipated to change during the entire course of the trial. Long-term psychotherapy is permitted as long as patients are not in an exposure phase during the trial. Diagnosis of a current moderate or severe alcohol use disorder according to MINI within 3 months prior to screening visit (mild alcohol use disorder (AUD) and patients in early remission = criterion not met for between 3 & 12 months are allowed) Further exclusion criteria apply