title: Sudden gains in Cognitive Therapy and Interpersonal Psychotherapy for adult depression.
abstract: OBJECTIVE
  We examined the rates, baseline predictors and clinical impact of sudden gains in a randomized comparison of individual Cognitive Therapy (CT) and Interpersonal Psychotherapy (IPT) for adult depression.
  
  
  METHODS
  117 depressed outpatients received 16-20 sessions of either CT or IPT. Session-by-session symptom severity was assessed using the BDI-II. Sudden gains were examined using the original criteria as defined by Tang and DeRubeis (1999b). Furthermore, we examined whether the duration of the between-session interval at which sudden gains were recorded affected the results.
  
  
  RESULTS
  There were significantly more patients with sudden gains in CT (42.2%) as compared to IPT (24.5%). The difference appeared to be driven by the criterion representing the stability of the gain. No between-group differences were found with regard to the magnitude, timing and predictors of the gains. Those with sudden gains were less depressed at post-treatment and follow-up. After controlling for the duration of the between-session interval, the difference in rates between the two conditions became a non-significant trend. Other sudden gains characteristics were similar to those observed when allowing for longer intervals as well.
  
  
  CONCLUSIONS
  The current study indicates differences in occurrence of sudden gains in two treatment modalities that overall showed similar results, which might reflect different mechanisms of change.
authors.affiliation: Department of Clinical Psychological Science, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands. Electronic address: Lotte.Lemmens@Maastrichtuniversity.nl.
authors.forename: Lotte H J M
authors.initials: LH
authors.lastname: Lemmens
authors.affiliation: Department of Psychology, University of Pennsylvania, 3720 Walnut Street, Philadelphia, PA 19104-6241, USA.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: DeRubeis
authors.affiliation: Department of Clinical Psychological Science, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; Department of Clinical Psychology, University of Amsterdam, P.O. Box 19268, 1000 GG Amsterdam, The Netherlands.
authors.forename: Arnoud
authors.initials: A
authors.lastname: Arntz
authors.affiliation: Department of Psychiatry and Psychology, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, The Netherlands.
authors.forename: Frenk P M L
authors.initials: FP
authors.lastname: Peeters
authors.affiliation: Department of Clinical Psychological Science, Maastricht University, P.O. Box 616, 6200 MD Maastricht, The Netherlands; Department of Psychology, University of Pennsylvania, 3720 Walnut Street, Philadelphia, PA 19104-6241, USA; Department of Clinical Psychology, VU University Amsterdam, Van der Boechorststraat 1, 1081 BT Amsterdam, The Netherlands.
authors.forename: Marcus J H
authors.initials: MJ
authors.lastname: Huibers
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015928:Cognitive Behavioral Therapy / Q000379:methods*; D003863:Depression / Q000523:psychology; D003866:Depressive Disorder / Q000628:therapy*; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D011613:Psychotherapy / Q000379:methods*; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
keywords: Cognitive Therapy; Depression; Interpersonal Psychotherapy; RCT; Sudden gains