title: Anxiety Disorders are Associated with Reduced Heart Rate Variability: A Meta-Analysis.
abstract: BACKGROUND
  Anxiety disorders increase risk of future cardiovascular disease (CVD) and mortality, even after controlling for confounds including smoking, lifestyle, and socioeconomic status, and irrespective of a history of medical disorders. While impaired vagal function, indicated by reductions in heart rate variability (HRV), may be one mechanism linking anxiety disorders to CVD, prior studies have reported inconsistent findings highlighting the need for meta-analysis.
  
  
  METHODS
  Studies comparing resting-state HRV recordings in patients with an anxiety disorder as a primary diagnosis and healthy controls were considered for meta-analysis.
  
  
  RESULTS
  Meta-analyses were based on 36 articles, including 2086 patients with an anxiety disorder and 2294 controls. Overall, anxiety disorders were characterized by lower HRV [high frequency (HF): Hedges' g = -0.29. 95% CI: -0.41 to -0.17, p < 0.001; time domain: Hedges' g = -0.45, 95% CI: -0.57 to -0.33, p < 0.001] than controls. Panic disorder (n = 447), post-traumatic stress disorder (n = 192), generalized anxiety disorder (n = 68), and social anxiety disorder (n = 90), but not obsessive-compulsive disorder (n = 40), displayed reductions in HF HRV relative to controls (all ps < 0.001).
  
  
  CONCLUSIONS
  Anxiety disorders are associated with reduced HRV, findings associated with a small-to-moderate effect size. Findings have important implications for future physical health and well-being of patients, highlighting a need for comprehensive cardiovascular risk reduction.
authors: School of Psychology, University of Sydney , Sydney, NSW , Australia.
authors: John A
authors: JA
authors: Chalmers
authors: Brain and Mind Research Institute, University of Sydney , Sydney, NSW , Australia ; NORMENT, KG Jebsen Centre for Psychosis Research, Institute of Clinical Medicine, University of Oslo , Oslo , Norway ; Division of Mental Health and Addiction, Oslo University Hospital , Oslo , Norway.
authors: Daniel S
authors: DS
authors: Quintana
authors: School of Psychology, University of Sydney , Sydney, NSW , Australia.
authors: Maree J-Anne
authors: MJ
authors: Abbott
authors: School of Psychology, University of Sydney , Sydney, NSW , Australia ; University Hospital and Faculty of Medicine, University of São Paulo , São Paulo , Brazil ; Discipline of Psychiatry, University of Sydney , Sydney, NSW , Australia.
authors: Andrew H
authors: AH
authors: Kemp
keywords: anxiety; anxiety disorders; cardiovascular disease; heart rate variability; meta-analysis; treatment