title: Biomarkers and staging of bipolar disorder: a systematic review.
abstract: BACKGROUND
  A growing body of evidence suggests that bipolar disorder (BD) is a progressive disease according to clinical, biochemical and neuroimaging findings. This study reviewed the literature on the relationship between specific biomarkers and BD stages.
  
  
  METHODS
  A comprehensive literature search of MEDLINE and PubMed was conducted to identify studies in English and Portuguese using the keywords biomarker, neurotrophic factors, inflammation, oxidative stress, neuroprogression and staging models cross-referenced with bipolar disorder.
  
  
  RESULTS
  Morphometric studies of patients with BD found neuroanatomic abnormalities, such as ventricular enlargement, grey matter loss in the hippocampus and cerebellum, volume decreases in the prefrontal cortex and variations in the size of the amygdala. Other studies demonstrated that serum concentrations of neurotrophic factors, inflammatory mediators and oxidative stress may be used as BD biomarkers.
  
  
  CONCLUSIONS
  The analysis of neurobiological changes associated with BD progression and activity may confirm the existence of BD biomarkers, which may be then included in staging models that will lead to improvements in treatment algorithms and more effective, individually tailored treatment regimens. Biomarkers may also be used to define early interventions to control disease progression.
authors: Faculdade de Medicina de Lisboa, Lisbon, Portugal.
authors: Ângela
authors: Â
authors: Roda
authors: Faculdade de Medicina de Lisboa, University Clinic, Lisboa, Portugal.
authors: Inês
authors: I
authors: Chendo
authors: Department of Psychiatry, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil.
authors: Mauricio
authors: M
authors: Kunz
mesh_terms: D015415:Biomarkers / Q000378:metabolism; D001714:Bipolar Disorder / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology*; D018450:Disease Progression; D006801:Humans
chemical_list: D015415:Biomarkers