title: The effect of trauma-focused therapy on the altered T cell distribution in individuals with PTSD: evidence from a randomized controlled trial.
abstract: Posttraumatic stress disorder (PTSD) is associated with a reduced ratio of naïve cytotoxic T lymphocytes, an increased ratio of memory cytotoxic T lymphocytes, and a reduced proportion of FoxP3(+) regulatory T lymphocytes. This study investigated whether these immunological alterations are reversible through an evidence-based psychotherapeutic treatment. Therefore, 34 individuals with PTSD were randomly assigned to either a treatment condition of 12 sessions narrative exposure therapy (NET) or a waitlist control (WLC) group. PTSD symptoms were significantly reduced in the NET group, but not in the WLC group, four months post-therapy (effect size: Hedges' g = -1.61). One year after therapy, PTSD symptoms were improved even further in the NET group compared to baseline (Hedges' g = -1.96). This symptom improvement was mirrored in an increase in the originally reduced proportion of regulatory T cells (Tregs) in the NET group at the one-year follow-up, when comparing subgroups matched for baseline Treg numbers. However, no changes were found for the initially reduced proportion of CD45RA(+)CCR7(+) naïve T lymphocytes. In conclusion, NET was effective in reducing trauma-related PTSD symptoms and had a positive effect on the proportion of Tregs cells, thus demonstrating an effect of psychotherapy on an immunological level. Yet, the shift in the proportion of naïve and memory T lymphocytes in individuals with PTSD, discussed in the literature as a correlate of premature immunosenescence, was not reversible and thus might render these patients permanently more susceptible to infectious diseases.
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Morath
authors.affiliation: Clinical and Biological Psychology, Institute of Psychology and Education, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany.
authors.forename: Hannah
authors.initials: H
authors.lastname: Gola
authors.affiliation: Division of Immunology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany.
authors.forename: Annette
authors.initials: A
authors.lastname: Sommershof
authors.affiliation: Clinical and Biological Psychology, Institute of Psychology and Education, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany.
authors.forename: Gilava
authors.initials: G
authors.lastname: Hamuni
authors.affiliation: SAP Switzerland AG, Tägerwilen, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Kolassa
authors.affiliation: Clinical Psychology and Psychotherapy, University of Bielefeld, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Catani
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Germany.
authors.forename: Hannah
authors.initials: H
authors.lastname: Adenauer
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Germany.
authors.forename: Martina
authors.initials: M
authors.lastname: Ruf-Leuschner
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Germany.
authors.forename: Maggie
authors.initials: M
authors.lastname: Schauer
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Elbert
authors.affiliation: Division of Immunology, Department of Biology, University of Konstanz, 78457 Konstanz, Germany; Biotechnology Institute Thurgau at the University of Konstanz, 8280 Kreuzlingen, Switzerland.
authors.forename: Marcus
authors.initials: M
authors.lastname: Groettrup
authors.affiliation: Center of Excellence for Psychotraumatology, Clinical Psychology and Neuropsychology, University of Konstanz, Germany; Clinical and Biological Psychology, Institute of Psychology and Education, University of Ulm, Albert-Einstein-Allee 47, 89069 Ulm, Germany. Electronic address: Iris.Kolassa@uni-ulm.de.
authors.forename: Iris-Tatjana
authors.initials: IT
authors.lastname: Kolassa
mesh_terms: D000293:Adolescent; D000328:Adult; D015703:Antigens, CD; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007171:Implosive Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D018709:Statistics, Nonparametric; D013313:Stress Disorders, Post-Traumatic / Q000276:immunology / Q000523:psychology / Q000534:rehabilitation; D013601:T-Lymphocytes / Q000473:pathology*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015703:Antigens, CD
keywords: Narrative exposure therapy (NET); Posttraumatic stress disorder (PTSD); Psychotherapy; Regulatory T cells; T lymphocytes