title: Biological rhythm disturbance in remitted bipolar patients.
abstract: BACKGROUND
  Biological rhythm disturbance is common in bipolar patients and seems to affect the course and prognosis of the illness negatively. The main aim of the current study was to assess biological rhythms in remitted bipolar patients. We also assessed whether there was an association between clinical variables or functioning and biological rhythms in remitted bipolar participants.
  
  
  METHODS
  The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) was used to assess biological rhythm disturbance. It is an 18-item interviewer-administered instrument which allows us to investigate the main areas related to circadian rhythm disturbance (sleep/social, activities, and eating pattern) in bipolar disorder.
  
  
  CONCLUSIONS
  Bipolar patients (n = 107) experienced greater biological rhythm alterations than the control group (n = 100) (BRIAN total scores 35.36 ± 7.11 vs. 32.48 ± 6.10, t = 6.912, p = 0.002, Cohen's d = 0.43, r = 0.21). In particular, patients were more impaired than the control group with regard to sleep/social (14.67 ± 4.14 vs. 13.49 ± 2.91, t = 10.61, p = 0.018, Cohen's d = 0.33, r = 0.16) and activity (8.49 ± 2.51 vs. 7.07 ± 2.13, t = 3.90, p = 0.001, Cohen's d = 0.61, r = 0.29) domains. Furthermore, a significant correlation was found between biological rhythms with residual depressive symptoms (r = 0.459, p < 0.001) and functioning (r = 0.432, p < 0.001). These findings suggest a potential link between biological rhythms and the pathophysiology of bipolar disorder. It highlights the importance of novel instruments (e.g., BRIAN) which allow us to assess biological rhythm disturbance in psychiatry. Finally, specific psychosocial interventions focused on lifestyle regularity may be considered as a supplemental treatment of bipolar illness episodes.
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain ; Bipolar Disorders Program and INCT for Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350, Porto Alegre, Rio Grande do Sul 90035903 Brazil ; Centro Universitário La Salle, Rua Victor Barreto 2350, Canoas, Rio Grande do Sul 92010-000 Brazil.
authors.forename: Adriane R
authors.initials: AR
authors.lastname: Rosa
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Mercè
authors.initials: M
authors.lastname: Comes
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Carla
authors.initials: C
authors.lastname: Torrent
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Brisa
authors.initials: B
authors.lastname: Solè
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Maria
authors.initials: M
authors.lastname: Reinares
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Isabella
authors.initials: I
authors.lastname: Pachiarotti
authors.affiliation: Clinical Psychology Department, Institute of Neurosciences, Hospital Clinic, IDIBAPS, University of Barcelona, Villarroel 170, Barcelona, 08036 Spain.
authors.forename: Manel
authors.initials: M
authors.lastname: Salamero
authors.affiliation: Bipolar Disorders Program and INCT for Translational Medicine, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Ramiro Barcelos 2350, Porto Alegre, Rio Grande do Sul 90035903 Brazil.
authors.forename: Flávio
authors.initials: F
authors.lastname: Kapczinski
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Francesc
authors.initials: F
authors.lastname: Colom
authors.affiliation: Bipolar Disorders Program, Institute of Neurosciences, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Villarroel 170, Barcelona, Catalonia, 08036 Spain.
authors.forename: Eduard
authors.initials: E
authors.lastname: Vieta
keywords: Biological rhythms; Bipolar disorder; Circadian rhythms; Functioning; Sleep alterations