RecruitingBehavioural interventionA Comparative Effectiveness Study of PTSD Treatments Among Sexual and Gender Minority PopulationsThe goal of this clinical trial is see if Cognitive Processing Therapy and STAIR Narrative Therapy work to treat posttraumatic stress disorder (PTSD) among lesbian, gay, bisexual, transgender, queer/questioning, intersex, asexual/aromantic, and all other sexual or gender minority (LGBTQIA+) adults. The main questions it aims to answer are: * Do these treatments reduce PTSD symptoms in LGBTQIA+ patients? * Do these treatments help improve quality of life and reduce depression in LGBTQIA+ patients? * Do stress from stigma and discrimination and drug/alcohol use change the impact of the treatment on PTSD symptoms? * Are LGBTQIA+ patients satisfied with these treatments? Do these treatments work differently among different groups within the LGBTQIA+ community? * Do LGBTQIA+ patients complete these treatments? Study participants will receive one of these two PTSD treatments. Participants will complete assessments before and after receiving treatment.