title: Double trouble: does co-morbid chronic somatic illness increase risk for recurrence in depression? A systematic review.
abstract: OBJECTIVE
  To perform a systematic review, and if possible a meta-analysis, to establish whether depressed patients with co-morbid chronic somatic illnesses are a high risk "double trouble" group for depressive recurrence.
  
  
  METHODS
  The databases PubMed, EMbase and PsycINFO were systematically searched until the 4(th) of December 2012 by using MeSH and free text terms. Additionally, reference lists of retrieved publications and treatment guidelines were reviewed, and experts were consulted. Inclusion criteria were: depression had to be measured at least twice during the study with qualified instruments and the chronic somatic illness had to be assessed by self-report or by a medical professional. Information on depressive recurrence was extracted and additionally risk ratios of recurrence were calculated.
  
  
  RESULTS
  The search generated four articles that fulfilled our inclusion criteria. These studies showed no differences in recurrence over one- two- three- and 6.5 years of follow-up for a total of 2010 depressed patients of which 694 patients with a co-morbid chronic somatic illness versus 1316 patients without (Study 1: RR = 0.49, 95% CI, 0.17-1.41 at one year follow-up and RR = 1.37, 95% CI, 0.78-2.41 at two year follow-up; Study 2: RR = 0.94, 95% CI, 0.65-1.36 at two year follow-up; Study 3: RR = 1.15, 95% CI, 0.40-3.27 at one year follow-up; RR = 1.07, 95% CI, 0.48-2.42 at two year follow-up and RR = 0.99, 95% CI,0.55-1.77 at 6.5 years follow-up; Study 4: RR = 1.16, 95% CI, 0.86-1.57 at three year follow-up).
  
  
  CONCLUSIONS
  We found no association between a heightened risk for depressive recurrence and co-morbid chronic somatic illnesses. There is a need for more longitudinal studies to justify the current specific treatment advice such as long-term pharmacological maintenance treatment for this presumed "double trouble" group.
authors.affiliation: Department of Clinical Psychology, University of Groningen, Groningen, The Netherlands.
authors.forename: Gemma D
authors.initials: GD
authors.lastname: Kok
authors.forename: Claudi L H
authors.initials: CL
authors.lastname: Bockting
authors.forename: Huibert
authors.initials: H
authors.lastname: Burger
authors.forename: Wiebke
authors.initials: W
authors.lastname: Hannig
authors.forename: Gerdina H M
authors.initials: GH
authors.lastname: Pijnenborg
authors.forename: Pim
authors.initials: P
authors.lastname: Cuijpers
authors.forename: Steven D
authors.initials: SD
authors.lastname: Hollon
mesh_terms: D002908:Chronic Disease; D015897:Comorbidity; D003863:Depression / Q000150:complications*; D006801:Humans; D011379:Prognosis; D012008:Recurrence; D012307:Risk Factors