title: Experience sampling-based personalized feedback and positive affect: a randomized controlled trial in depressed patients.
abstract: OBJECTIVE
  Positive affect (PA) plays a crucial role in the development, course, and recovery of depression. Recently, we showed that a therapeutic application of the experience sampling method (ESM), consisting of feedback focusing on PA in daily life, was associated with a decrease in depressive symptoms. The present study investigated whether the experience of PA increased during the course of this intervention.
  
  
  METHODS
  Multicentre parallel randomized controlled trial. An electronic random sequence generator was used to allocate treatments.
  
  
  METHODS
  University, two local mental health care institutions, one local hospital.
  
  
  METHODS
  102 pharmacologically treated outpatients with a DSM-IV diagnosis of major depressive disorder, randomized over three treatment arms.
  
  
  METHODS
  Six weeks of ESM self-monitoring combined with weekly PA-focused feedback sessions (experimental group); six weeks of ESM self-monitoring combined with six weekly sessions without feedback (pseudo-experimental group); or treatment as usual (control group).
  
  
  RESULTS
  The interaction between treatment allocation and time in predicting positive and negative affect (NA) was investigated in multilevel regression models.
  
  
  RESULTS
  102 patients were randomized (mean age 48.0, SD 10.2) of which 81 finished the entire study protocol. All 102 patients were included in the analyses. The experimental group did not show a significant larger increase in momentary PA during or shortly after the intervention compared to the pseudo-experimental or control groups (χ2(2) = 0.33, p = .846). The pseudo-experimental group showed a larger decrease in NA compared to the control group (χ2(1) = 6.29, p =.012).
  
  
  CONCLUSIONS
  PA-focused feedback did not significantly impact daily life PA during or shortly after the intervention. As the previously reported reduction in depressive symptoms associated with the feedback unveiled itself only after weeks, it is conceivable that the effects on daily life PA also evolve slowly and therefore were not captured by the experience sampling procedure immediately after treatment.
  
  
  BACKGROUND
  Trialregister.nl/trialreg/index.asp. NTR1974.
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; GGzE, Institute of Mental Health Care Eindhoven and the Kempen, Eindhoven, The Netherlands; Orygen, the National Centre of Excellence in Youth Mental Health, University of Melbourne, Melbourne, Australia.
authors.forename: Jessica A
authors.initials: JA
authors.lastname: Hartmann
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands.
authors.forename: Marieke
authors.initials: M
authors.lastname: Wichers
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands.
authors.forename: Claudia
authors.initials: C
authors.lastname: Menne-Lothmann
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; GGzE, Institute of Mental Health Care Eindhoven and the Kempen, Eindhoven, The Netherlands.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Kramer
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Viechtbauer
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands.
authors.forename: Frenk
authors.initials: F
authors.lastname: Peeters
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; Center for Learning and Experimental Psychology, Faculty of Psychology, Leuven University, Leuven, Belgium.
authors.forename: Koen R J
authors.initials: KR
authors.lastname: Schruers
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; GGzE, Institute of Mental Health Care Eindhoven and the Kempen, Eindhoven, The Netherlands.
authors.forename: Alex L
authors.initials: AL
authors.lastname: van Bemmel
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands.
authors.forename: Inez
authors.initials: I
authors.lastname: Myin-Germeys
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; Mondriaan Mental Health Trust, South Limburg, The Netherlands.
authors.forename: Philippe
authors.initials: P
authors.lastname: Delespaul
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; King's College London, Department of Psychosis Studies, Institute of Psychiatry, London, United Kingdom.
authors.forename: Jim
authors.initials: J
authors.lastname: van Os
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University Medical Centre, European Graduate School of Neuroscience, SEARCH, Maastricht, The Netherlands; GGzE, Institute of Mental Health Care Eindhoven and the Kempen, Eindhoven, The Netherlands.
authors.forename: Claudia J P
authors.initials: CJ
authors.lastname: Simons
mesh_terms: D000339:Affect / Q000502:physiology*; D003863:Depression / Q000523:psychology* / Q000628:therapy*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012648:Self Care