title: Predicting trauma-focused treatment outcome in psychosis.
abstract: Although TF treatments are effective in patients with psychosis, it is unknown whether specific psychosis-related obstacles limit the effects, and what determines good outcome.
  
  
  
  Baseline posttraumatic stress disorder (PTSD) symptom severity and seven psychosis-specific variables were tested as predictors in patients with a psychotic disorder and PTSD (n=108), who received eight sessions of TF treatment (Prolonged Exposure, or Eye Movement Desensitization and Reprocessing therapy) in a single-blind randomized controlled trial. Multiple regression analyses were performed.
  
  
  
  Baseline PTSD symptom severity was significantly associated with posttreatment PTSD symptom severity, explaining 11.4% of the variance. Additionally, more severe PTSD at baseline was also significantly associated with greater PTSD symptom improvement during treatment. After correction for baseline PTSD symptom severity, the model with the seven baseline variables did not significantly explain the variance in posttreatment PTSD outcome. Within this non-significant model, the presence of auditory verbal hallucinations contributed uniquely to posttreatment outcome but explained little variance (5.4%). Treatment completers and dropouts showed no significant difference on any of the psychosis-related variables.
  
  
  
  Given the low predictive utility of baseline psychosis-related factors, we conclude that there is no evidence-based reason to exclude patients with psychotic disorders from TF treatments. Also, we speculate that patients with psychosis and severe baseline PTSD might derive more benefit if given more than eight sessions. Trial registration current controlled-trials.com | Identifier: ISRCTN79584912 | http://www.isrctn.com/ISRCTN79584912.
authors.affiliation: Parnassia Psychiatric Institute, Zoutkeetsingel 40, 2512 HN Den Haag, The Netherlands. Electronic address: d.vandenberg@parnassia.nl.
authors.forename: David P G
authors.initials: DPG
authors.lastname: van den Berg
authors.affiliation: Community Mental Health Service GGZ Noord-Holland Noord, Oude Hoeverweg 10, 1816 BT Alkmaar, The Netherlands. Electronic address: b.vandervleugel@ggz-nhn.nl.
authors.forename: Berber M
authors.initials: BM
authors.lastname: van der Vleugel
authors.affiliation: Mental Health Organization (MHO) GGZ Oost Brabant Land van Cuijk en Noord Limburg, Bilderbeekstraat 44, 5831 CX Boxmeer, The Netherlands. Electronic address: paj.de.bont@ggzoostbrabant.nl.
authors.forename: Paul A J M
authors.initials: PAJM
authors.lastname: de Bont
authors.affiliation: Altrecht Psychiatric Institute, ABC straat 8, 3512 PX Utrecht, The Netherlands. Electronic address: t.staring@altrecht.nl.
authors.forename: Anton B P
authors.initials: ABP
authors.lastname: Staring
authors.affiliation: Parnassia Psychiatric Institute, Zoutkeetsingel 40, 2512 HN Den Haag, The Netherlands. Electronic address: t.kraan@parnassia.nl.
authors.forename: Tamar
authors.initials: T
authors.lastname: Kraan
authors.affiliation: Parnassia Psychiatric Institute, Zoutkeetsingel 40, 2512 HN Den Haag, The Netherlands. Electronic address: h.ising@parnassia.nl.
authors.forename: Helga
authors.initials: H
authors.lastname: Ising
authors.affiliation: MHO Rivierduinen, Sandifortdreef 19, 2333 ZZ Leiden, The Netherlands. Electronic address: c.deroos@rivierduinen.nl.
authors.forename: Carlijn
authors.initials: C
authors.lastname: de Roos
authors.affiliation: Dept of Behavioral Sciences, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands; School of Health Sciences, Salford University, Manchester, United Kingdom. Electronic address: a.de.jongh@acta.nl.
authors.forename: Ad
authors.initials: A
authors.lastname: de Jongh
authors.affiliation: Radboud University Nijmegen, Behavioural Science Institute, NijCare, P.O. Box 9104, 6500 HE Nijmegen, The Netherlands; MHO Pro Persona, Centre for Anxiety Disorders Overwaal, Nijmegen, The Netherlands. Electronic address: a.van.minnen@propersona.nl.
authors.forename: Agnes
authors.initials: A
authors.lastname: van Minnen
authors.affiliation: Parnassia Psychiatric Institute, Zoutkeetsingel 40, 2512 HN Den Haag, The Netherlands; VU University Amsterdam and EMGO Institute for Health and Care Research, Department of Clinical Psychology, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands. Electronic address: m.vander.gaag@vu.nl.
authors.forename: Mark
authors.initials: M
authors.lastname: van der Gaag
mesh_terms: D000328:Adult; D015897:Comorbidity; D057169:Eye Movement Desensitization Reprocessing; D005260:Female; D006212:Hallucinations / Q000150:complications / Q000188:drug therapy; D006801:Humans; D008297:Male; D010352:Patient Dropouts; D011379:Prognosis; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000150:complications* / Q000188:drug therapy / Q000523:psychology; D012044:Regression Analysis; D012720:Severity of Illness Index; D016037:Single-Blind Method; D013313:Stress Disorders, Post-Traumatic / Q000150:complications* / Q000628:therapy*; D016896:Treatment Outcome
keywords: Eye movement desensitization and reprocessing; PTSD; Prediction; Prolonged exposure