ACTRN12614001213639.

Study name	Internet treatment for posttraumatic stress disorder (PTSD).
Methods	Randomised controlled trial using a list generated prior to the study. For allocation concealment, a staff member not involved in the clinical trial will generate the sequence using computer software and place each choice in a sequentially numbered, opaque sealed and stapled envelope.
Participants	Inclusion criteria Self‐identified as having PTSD/experienced a major trauma Meet criteria for PTSD as determined by MINI Australian residential status Aged ≥ 18 years Access to a computer, Internet, and printer If taking medication, must have been taking the same dose for ≥ 1 month and not intend to change that dose during the course of the programme Prepared to provide name, telephone number, and address, and to provide the name and address of a local general practitioner Willing to provide written informed consent Exclusion criteria Does not meet PTSD diagnostic criteria Trauma occurrence within the past 4 weeks Currently participating in CBT or other treatment for trauma or PTSD Currently highly dissociative (indicated by score ≥ 40 on the DES) Current or pending medicolegal proceedings associated with the reported trauma Applying for or receiving Workers Compensation associated with their trauma or PTSD Regularly using illicit drugs or regularly consuming more than 3 standard drinks a day Current regular use of benzodiazepines Currently experiencing a psychotic mental illness or bipolar disorder Severe symptoms of depression (defined as a total score ≥ 22 or responding at least '2' to Question 9 (suicidal ideation) on PHQ‐9
Interventions	Experimental arm The Internet PTSD program comprises 6 lessons completed over 10 weeks. 1 lesson will be completed every 7–14 days with a minimum of 5 days between lessons and a maximum of 14 days. Comparator arm Wait list control. Participants remain on the wait list until the immediate treatment group has completed their treatment and post‐treatment assessment (11 weeks). At that time (11 weeks), the wait list control group will be offered the same Internet treatment program for PTSD.
Outcomes	Time point for assessment: 1‐week post‐treatment, 3‐months post‐treatment, 6‐months post‐treatment Primary outcomes: PTSD (PCL‐C) Secondary outcomes: PHQ‐9, K10, CEQ, SDS, IUS‐12, ERQ, WHODAS‐II
Starting date	14 September 2014
Contact information	Prof Gavin Andrews Clinical Research Unit for Anxiety and Depression, 390 Victoria St, Darlinghurst, Australia gavina@unsw.edu.au
Notes	www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=366115