Therapies presented here have a robust evidence base and were selected based on a meta-analysis that investigated the effectiveness of group therapy for PTSD (Schwartze et al., 2017). For a study to be included, we considered systematic reviews and meta-analyses only, published from 1990 on with no restrictions on publication language and involving adult patients (>= 18 years) with a diagnosis of PTSD according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-III-R, DSM-IV, DSM-IV-TR, DSM-V; American Psychiatric Association 1987, 1994, 2000, 2013) or the International Classification of Diseases (ICD-10; World Health Organization, 1992). Additionally, studies must have been based upon a psychotherapeutic formal change theory, performed by a professional group leader or therapist in groups comprising at least three patients, lasting at least for five sessions. Eligible control groups were “no treatment/wait-list control”, “treatment as usual”, “common factor control”, “individual psychotherapy” as well as “pharmacotherapy”. Clinician-rated symptom severity was considered as the primary outcome. 

Each disorder included had more than 2 trials given the amount of research attention PTSD has received. One caution about the evidence is the inclusion of not randomized-controlled trials only which limits the establishment of causal associations and thereby the level of evidence (Zabor et al., 2020).  

Although not originally intended for group therapy, some of the provided resources can be effectively utilized in a group setting. Furthermore, the page on promising therapies for PTSD introduces additional treatment alternatives that have shown promising findings in ongoing research.