title: Emergent anxiety after antidepressant initiation: a retrospective cohort study of Veterans Affairs Health System patients with depression.
abstract: BACKGROUND
  Initiation of antidepressant treatment for depression may be associated with new onset (emergent) anxiety.
  
  
  OBJECTIVE
  The purpose of this study was to assess demographic and clinical factors associated with emergent anxiety following a new antidepressant start among Department of Veterans Affairs (VA) Health System patients with depression.
  
  
  METHODS
  Using a retrospective cohort design, we obtained data from 328,888 VA patients with depression who were newly prescribed 1 of the 7 most commonly used antidepressant drugs between April 1999 and September 2004 from the VA National Depression Registry. We examined the prevalence of emergent anxiety, defined as either a new anxiety diagnoses or by new antianxiety medication starts, during the 12 weeks following new antidepressant start. In multivariate analyses, we assessed the hazard ratios for emerging anxiety associated with patient characteristics and specific antidepressant agents.
  
  
  RESULTS
  Approximately 3% of patients developed clinically significant anxiety within 12 weeks of starting an antidepressant drug regimen. Younger age (age <45 years and 45-64 years) was associated with higher risks for emergent anxiety than older age (≥65 years) (hazard ratio [HR] = 1.72 and 1.55; 95% CI, 1.59-1.85, and 1.38-1.72, respectively). Female gender was associated with higher risks than male gender (HR = 1.17; 95% CI, 1.10-1.26), and white and other races compared with black race were associated with higher risks of emergent anxiety (HR = 1.49 and 1.13; 95% CI, 1.30-1.59 and 1.04-1.23, respectively). Finally, filling antidepressant drug prescriptions in years subsequent to 1999 was associated with lower risks of emergent anxiety.
  
  
  CONCLUSIONS
  Only a small proportion of patients developed emergent anxiety following a new antidepressant start, resulting in a new diagnosis or antianxiety medication use. Anxiety occurred more often in young adults, whites, and women.
authors.affiliation: Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, North Carolina 27710, USA. zhiguo.li@duke.edu
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: Li
authors.forename: Paul N
authors.initials: PN
authors.lastname: Pfeiffer
authors.forename: Katherine J
authors.initials: KJ
authors.lastname: Hoggatt
authors.forename: Kara
authors.initials: K
authors.lastname: Zivin
authors.forename: Karen
authors.initials: K
authors.lastname: Downing
authors.forename: Dara
authors.initials: D
authors.lastname: Ganoczy
authors.forename: Marcia
authors.initials: M
authors.lastname: Valenstein
mesh_terms: D000367:Age Factors; D000368:Aged; D014151:Anti-Anxiety Agents / Q000627:therapeutic use; D000928:Antidepressive Agents / Q000009:adverse effects*; D001007:Anxiety / Q000139:chemically induced* / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D003863:Depression / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology / Q000523:psychology; D005260:Female; D006307:Health Systems Agencies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D016016:Proportional Hazards Models; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014493:United States Department of Veterans Affairs; D044465:White People
chemical_list: D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents