title: Circadian rest-activity rhythm in individuals at risk for psychosis and bipolar disorder.
abstract: BACKGROUND
  At-risk mental states (ARMS) are clinical syndromes that are associated with higher risk, compared with the general population, for developing psychosis and bipolar disorder. Circadian rhythm misalignments have been proposed to be part of this early phase of the clinical course.
  
  
  OBJECTIVE
  To compare circadian rhythm of activity and rest changes between ARMS individuals and a healthy control group.
  
  
  METHODS
  Forty volunteers of both genders, aged between 13 and 27years old, participated in this study (n=20 ARMS group, and n=20 healthy controls). The ARMS individuals were classified as ultra-high risk for psychosis according to the CAARMS (Comprehensive Assessment of At-risk Mental State) or at high risk for bipolar disorder according to criteria proposed by Bechdolf and colleagues. Participants used an actigraph for fifteen days, kept a sleep diary, and completed the Epworth Sleepiness Scale, the Pittsburgh Sleep Quality Index, and a Morningness-Eveningness Questionnaire.
  
  
  RESULTS
  Compared with healthy volunteers, the ARMS group presented worse sleep quality (P=0.010); longer nap durations (P=0.038), shorter wake times (P=0.001), higher total sleep times (P=0.011), and shorter activity duration (P=0.021), sleep rhythms were more fragmented, the circadian rest-activity rhythms were less synchronized with the dark-light cycle and had lower amplitudes of motor activity.
  
  
  CONCLUSIONS
  The results suggest alterations in the circadian rest-activity rhythms (and likely in sleep-wake cycle patterns) in ARMS individuals compared with healthy controls. It is possible that circadian rhythms of activity and rest changes are one of the prodromal clinical and behavioral expressions of the brain changes that underlie ARMS individuals.
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil. Electronic address: juvilela.castro@gmail.com.
authors.forename: Juliana
authors.initials: J
authors.lastname: Castro
authors.affiliation: PRISMA/PROESQ - Departamento de Psiquiatria, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Marcio
authors.initials: M
authors.lastname: Zanini
authors.affiliation: Instituto Federal Sudeste de Minas Gerais, Campus Barbacena, Barbacena, Brazil.
authors.forename: Bruno da Silva Brandão
authors.initials: Bda S
authors.lastname: Gonçalves
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil; Departamento de Neurologia e Neurocirurgia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Fernando Morgadinho Santos
authors.initials: FM
authors.lastname: Coelho
authors.affiliation: PRISMA/PROESQ - Departamento de Psiquiatria, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Bressan
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Lia
authors.initials: L
authors.lastname: Bittencourt
authors.affiliation: PRISMA/PROESQ - Departamento de Psiquiatria, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Ary
authors.initials: A
authors.lastname: Gadelha
authors.affiliation: PRISMA/PROESQ - Departamento de Psiquiatria, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Elisa
authors.initials: E
authors.lastname: Brietzke
authors.affiliation: Departamento de Psicobiologia, Universidade Federal de Sao Paulo, Sao Paulo, Brazil.
authors.forename: Sergio
authors.initials: S
authors.lastname: Tufik
mesh_terms: D056044:Actigraphy; D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000503:physiopathology*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D011618:Psychotic Disorders / Q000175:diagnosis / Q000503:physiopathology*; D012146:Rest / Q000502:physiology*; D012890:Sleep / Q000502:physiology; D018709:Statistics, Nonparametric; D055815:Young Adult
keywords: Actigraphy; At-risk mental states; Bipolar disorder; Circadian rhythm; Psychosis; Ultra-high risk