Prognostics in the Treatment Evaluation of the National System for Veterans' Care

Veterans with posttraumatic stress disorder (PTSD) benefit less from
psychotherapy than non-military populations. Identification of predictors of
treatment outcome may provide insights to guide treatment selection and develop
personalized treatment strategies. We expect that a prognostic approach that
extends regular diagnostic assessment with an assessment of predictors across
multiple domains: psychodiagnostic (PD), neuropsychological (NP), and
psychophysiological (PP), will have a higher prognostic value than using
predictors within a single domain.

The primary objective of this project is to investigate whether using
prognostic factors from the PD, NP and PP domain will lead to a better
prediction of treatment outcome in veterans with PTSD. Our secondary objective
is to investigate whether the change in PD, NP, and PP factors is related to
treatment outcome in veterans with PTSD.

In this observational cohort study, we will prospectively examine predictors of
treatment outcome in veterans with PTSD. To this end, some additional
measurements will be performed besides regular clinical assessments. This
concerns the assessment of candidate predictors in three clinically relevant
domains: PD, NP, and PP. All patients will be assessed before the start of
treatment (T1) and follow-up assessments will be completed after 6 (T2) and 12
months (T3). This will be a multicenter study performed at treatment centers of
the National System for Veterans* Care (Dutch: LZV).

The burden associated with participation in this study is limited and the risk
is negligible. In this observational study, three additional assessments will
take place parallel to regular diagnostic assessment and treatment. The total
time of the three assessments (T1, T2, and T3) is about 8 h. Two assessments
(T1 and T3) will measure prognostic factors in all three domains: PD, NP, and
PP. The intermediate assessment (T2) consists of a short set of online
questionnaires. The PD measurements consist of structured interviews and
several online questionnaires. The NP examination consists of
neuropsychological tests. The PP measurements will include a physical
examination, a blood pressure assessment, monitoring of heart rate, a blood
sample, and a hair sample. In addition, we will ask participants to perform a
dexamethasone suppression test at home, which involves taking 5 salivary
samples on the first day, ingestion of 0,25 mg dexamethasone in the evening and
4 salivary samples the next day. Dexamethasone is given in a physiological dose
of which no side effects are expected. The burden associated with participating
primarily concerns time to perform the additional measurements and patients can
experience it as confronting to talk about their traumatic experiences and
symptoms in structured interviews. Patients do not directly benefit from
participating in the current study. However, patients will be able to receive a
personal report with results of the additional assessments. This study will
provide knowledge about the contribution of various clinically relevant factors
to treatment outcome. This knowledge could contribute to more focused
treatment, is relevant to develop personalized treatment strategies, and better
treatment outcomes for veterans with PTSD. Given the purpose and relevance of
the study, the burden and risk associated with participation are acceptable.