title: Effectiveness of a web-based cognitive behavioural intervention for subthreshold depression: pragmatic randomised controlled trial.
abstract: BACKGROUND
  Research on the effectiveness of treatments for subthreshold depression (sD) is still scarce. The aim of the study was to evaluate the efficacy of a web-based guided self-help intervention (GET.ON Mood Enhancer) in the treatment of sD.
  
  
  METHODS
  Participants with sD (n = 406) recruited from the general population via a large health insurance company were randomly allocated to a web-based cognitive behavioural intervention or to enhanced care-as-usual. The primary outcome was the reduction in depressive symptom severity as measured with the Center for Epidemiological Studies Depression Scale at post-treatment and at 6-month follow-up.
  
  
  RESULTS
  Participants in the intervention group showed a significantly greater pre-post reduction in depressive symptom severity (d = 1.06; 95% CI: 0.86-1.27) compared to the control condition (d = 0.29; 95% CI: 0.10-0.49). The corresponding between-group effect size was d = 0.69 (95% CI: 0.49-0.89). At 6-month follow-up the effect was reduced to d = 0.28 (95% CI: 0.09-0.48) but was still statistically significant (F1, 403 = 9.240, p = 0.003).
  
  
  CONCLUSIONS
  This study lends support to the idea that problem solving coupled with behavioural activation is an effective treatment for sD. In addition, the delivery of this intervention over the Internet might be a promising strategy for the dissemination of psychological interventions for sD on a large scale.
authors.affiliation: Innovation Incubator, Division of Online Health Training, Leuphana University, Lx00FC;neburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Buntrock
authors.forename: David
authors.initials: D
authors.lastname: Ebert
authors.forename: Dirk
authors.initials: D
authors.lastname: Lehr
authors.forename: Heleen
authors.initials: H
authors.lastname: Riper
authors.forename: Filip
authors.initials: F
authors.lastname: Smit
authors.forename: Pim
authors.initials: P
authors.lastname: Cuijpers
authors.forename: Matthias
authors.initials: M
authors.lastname: Berking
mesh_terms: D000328:Adult; D000339:Affect; D015928:Cognitive Behavioral Therapy; D003863:Depression / Q000628:therapy*; D005260:Female; D015438:Health Behavior; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D011340:Problem Solving; D011569:Psychiatric Status Rating Scales; D012648:Self Care; D011795:Surveys and Questionnaires; D016896:Treatment Outcome