Table 1 Therapist-assisted, online psychological therapies for posttraumatic stress disorder (STOP-PTSD) inclusion and exclusion criteria

Inclusion criteria

Participants must meet the following criteria:

1. Aged 18 years and above

2. Willing and able to provide informed consent

Meet the diagnostic criteria for PTSD as determined by the Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [21]

3. Their current reexperiencing symptoms are linked to one or two discrete traumatic events that they experienced in adulthood or adolescence, or several traumatic episodes during a longer period of high threat (e.g. domestic abuse, war zone experiences)

4. PTSD is the main psychological problem needing treatment

5. Able to read and write in English

6. Access to the Internet

7. Willing to be randomly allocated to one of the psychological treatments or wait-list

8. If taking psychotropic medication, the dose must be stable for at least 1 month before randomisation

9. If currently receiving psychological therapy for PTSD, this treatment must have ended before randomisation

Exclusion criteria

A person is not eligible if any of the following apply (assessed by clinician in the initial clinical assessment);

1. History of psychosis

2. Current substance dependence

3. Current borderline personality disorder

4. Acute serious suicide risk