A Phase 2 Single-site, Double-blind, Placebo-controlled, Randomized Clinical Trial With an Open-label Extension Phase to Examine the Safety, Subjective Experiences, Acute Effects, and Suitability of Psilocybin Combined With Psychological Support (Psi-PS) for Military Veterans and First Responders With Co-occurring Alcohol Use Disorder (AUD) and Posttraumatic Stress Disorder (PTSD) - Nathan Brashares Sackett (ClinicalTrials.gov, 2025)