title: Prevalence of bipolar disorder in panic disorder patients in the Japanese population.
abstract: BACKGROUND
  We examined the rate of bipolar I (BPD-I) and bipolar II disorders (BPD-II) in panic disorder (PD) patients, and compared clinical and psychological variables between PD patients with and without bipolar disorders (BPD).
  
  
  METHODS
  Participants were 649 Japanese patients with PD (215 men and 434 women, 38.49 ± 10.40 years) at outpatient clinics for anxiety disorders. Constructive interviews using the Mini-International Neuropsychiatric Interview (MINI) were conducted to confirm the diagnosis of PD, agoraphobia, and BPD, as well as the presence and severity of suicide risk in each subject. Clinical records were also reviewed to confirm the diagnosis of PD and BPD. Participants then completed several questionnaires, including the State Trait Anxiety Inventory-Trait scale, the Anxiety Sensitivity Index, and the Revised Neuroticism-Extraversion- Openness Personality Inventory (NEO-PI-R).
  
  
  RESULTS
  We found that 22.34% of the PD patients had BPD (BPD-I: 5.24%, BPD-II: 17.10%). PD patients with BPD-I showed higher prevalence and severity of suicide risk, trait anxiety, anxiety sensitivity, and neuroticism, and lower agreeableness (subscales of the NEO-PI-R) than those with BPD-II and those without BPD.
  
  
  CONCLUSIONS
  First, we could not investigate the order of the onset of PD and BPD. Second, BPD patients without PD were not studied as another control group for PD patients with BPD.
  
  
  CONCLUSIONS
  PD patients had high prevalence of BPD. Both PD patients with BPD-I and those with BPD-II had high severity of suicide risk, trait anxiety, anxiety sensitivity, neuroticism, and agreeableness, though these characteristics were more prominent in patients with BPD-I.
authors.affiliation: Addictive Substance Project, Tokyo Metropolitan Institute of Medical Science, Japan.
authors.forename: Nagisa
authors.initials: N
authors.lastname: Sugaya
authors.forename: Eiji
authors.initials: E
authors.lastname: Yoshida
authors.forename: Shin
authors.initials: S
authors.lastname: Yasuda
authors.forename: Mamoru
authors.initials: M
authors.lastname: Tochigi
authors.forename: Kunio
authors.initials: K
authors.lastname: Takei
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Otani
authors.forename: Takeshi
authors.initials: T
authors.lastname: Otowa
authors.forename: Takanobu
authors.initials: T
authors.lastname: Minato
authors.forename: Tadashi
authors.initials: T
authors.lastname: Umekage
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Konishi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakano
authors.forename: Junwen
authors.initials: J
authors.lastname: Chen
authors.forename: Shinobu
authors.initials: S
authors.lastname: Nomura
authors.forename: Yuji
authors.initials: Y
authors.lastname: Okazaki
authors.forename: Hisanobu
authors.initials: H
authors.lastname: Kaiya
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Sasaki
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tanii
mesh_terms: D000328:Adult; D000379:Agoraphobia / Q000453:epidemiology* / Q000523:psychology; D001714:Bipolar Disorder / Q000453:epidemiology* / Q000523:psychology; D015897:Comorbidity; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D016584:Panic Disorder / Q000453:epidemiology* / Q000523:psychology; D015995:Prevalence