Efficacy of Internet-delivered Trauma-focused CBT for Young People With PTSD

The CAPS-5-CA is a structured interview that assesses the Diagnostic and Statistical Manual of Mental Disorders version 5 (DSM-5) criteria for PTSD (Weathers et al., 2013). Each item is rated on a severity scale ranging from 0 (Absent) to 4 (Extreme/incapacitating) and combines information about frequency and intensity for each of the 20 symptoms. Total Score (Range 0-80 with higher scores representing more PTSD symptoms.

The CATS-2 measures potentially traumatic events (PTEs), posttraumatic stress symptoms (PTSS) and impairment according to DSM-5 and ICD-11 criteria in children and adolescent from 7 to 17 years. In addition to a self-report measure for children and adolescents, the CATS-2 includes a parallel caregiver version. Posttraumatic stress symptoms in the last four weeks are then assessed using 25 items rated on a 4-point. The 25 items map directly onto the diagnostic criteria for PTSD in DSM-5 and ICD-11 PTSD and CPTSD. The DSM-5 PTSD severity score is the sum of items 1-20 (range 0-60), including only the highest score of items 9, 10, 15. The ICD-11 PTSD severity score (range 0-18) is the sum of items 2, 3, 6, 7, 17, 18. The ICD-11 CPTSD score (range 0-36) is the sum of ICD-11 PTSD severity score (2, 3, 6, 7, 17, 18) plus the sum of the ICD-11 DSO severity score (9b, 9d, 10a, 13, 14, 15a). Higher scores represents more PTSD symptoms.

The MFQ consists of a series of 33 descriptive phrases regarding how the subject has been feeling or acting recently. Respondents are asked whether descriptions in the questionnaire are 'true', 'sometimes true' or 'not true' for them over the past two weeks. The MFQ is scored by summing together the point values of responses for each item. The response choices and their designated point values are as follows: "not true" = 0 points, "sometimes true" = 1 point, "true" = 2 points. Higher scores on the MFQ suggest more severe depressive symptoms.

EWSAS is a short, self-reported instrument consisting of five items about psychosocial impairments rated on a nine-point Likert scale. A higher score means more severe impairment.

Self-rated questionnaire on healthcare utilization and productivity losses in patients with a psychiatric disorder. The TIC-P questionnaire measures costs in two dimensions: use of health resources and loss of productivity. Lower cost is better.

Self-rated questionnaire on negative effects. It contains 32 items that are scored on a five point Likert-scale (0-4) and differentiates between negative effects that are attributed to treatment and those possibly caused by other circumstances. The total score of the NEQ ranges from 0 to 80 points, a higher score reflects more negative effects.

Change in subjective psychological, mental and social well-being from baseline to immediately after treatment and follow up . a higher score reflects higher health-related quality of life.

The CSQ-8 yields a single score measuring a single dimension of overall satisfaction. An "overall score" is calculated by summing the score on each of the eight scale item. Scores range from 8 to 32, with higher values indicating higher satisfaction.

Data will be gathered on total number of completed modules during the 12 week treatment.

Data will be gathered on total number of messages sent and received back and forth between the participant and the therapist during the 12 week treatment.

umber of home work assignments made by the participant during the treatment period

The proportion of participants that conducts the weekly measures and further assessment points

The proportion of participants that go through the entire treatment period

Number of drop-outs from treatment

Participants experience/satisfaction with treatment and assessment procedures through qualitative interviews

Measures treatment expectancy and rationale credibility. The CEQ is a 5-item measure of the treatment's credibility and the patients' expectations. The patients assess each domain on a 11-point likert scale (scored 0-10), with a total score ranging between 0-50 where higher score indicates higher credibility and higher expectations.

Measures the therapeutic alliance in therapy. The WAI-SR is a 12-item measure of the patient's experience of their working alliance with the therapist. The patients assess each item on a 7-point likert scale (scored 0-6), with a total score ranging between 0-72 where higher score indicates higher better working alliance according to the patient.