title: CO2-induced panic attacks: a twin study.
abstract: OBJECTIVE
  The authors investigated the role of genetic factors in 35% CO2-induced panic attacks.
  
  
  METHODS
  Ninety twins recruited from the general population were challenged with one-vital-capacity inhalations of 35% CO2-65% O2. Probandwise concordance rates were calculated and rates compared for monozygotic and for dizygotic twins.
  
  
  RESULTS
  A significantly higher concordance was found for 35% CO2-induced panic attacks among monozygotic than dizygotic twins (55.6% versus 12.5%).
  
  
  CONCLUSIONS
  These results suggest a relevant role of genetic factors in 35% CO2-induced panic attacks.
authors.affiliation: Department of Neuropsychiatric Sciences, Istituto Scientifico H.S. Raffaele, Milan, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Bellodi
authors.forename: G
authors.initials: G
authors.lastname: Perna
authors.forename: D
authors.initials: D
authors.lastname: Caldirola
authors.forename: C
authors.initials: C
authors.lastname: Arancio
authors.forename: A
authors.initials: A
authors.lastname: Bertani
authors.forename: D
authors.initials: D
authors.lastname: Di Bella
mesh_terms: D000328:Adult; D002245:Carbon Dioxide / Q000008:administration & dosage / Q000494:pharmacology; D004200:Diseases in Twins / Q000453:epidemiology / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008297:Male; D008957:Models, Genetic; D016584:Panic Disorder / Q000139:chemically induced* / Q000453:epidemiology / Q000235:genetics*; D015995:Prevalence; D012737:Sex Factors; D014429:Twins, Dizygotic / Q000235:genetics / Q000706:statistics & numerical data; D014430:Twins, Monozygotic / Q000235:genetics / Q000706:statistics & numerical data
chemical_list: D002245:Carbon Dioxide