title: Seasonal influences on first-episode admission in affective and non-affective psychosis.
abstract: BACKGROUND
  Since bipolar affective disorder has been recorded, clinicians treating patients with this disorder have noted the cyclic nature of episodes, particularly an increase in mania in the spring and summer months and depression during winter.
  
  
  OBJECTIVE
  The aim of this study was to investigate seasonality in symptom onset and service admissions over a period of 10 years in a group of patients (n= 359) with first-episode (FE) mania (n= 133), FE schizoaffective disorder (n= 49) and FE schizophrenia (n= 177).
  
  
  METHODS
  Patients were recruited if they were between 15 and 28 years of age and if they resided in the geographical mental health service catchment area. The number of patients experiencing symptom onset and service admission over each month and season was recorded.
  
  
  RESULTS
  In terms of seasonality of time of service admission, the results indicate a high overall seasonality (particularly in men), which was observed in both the schizoaffective and the bipolar groups. In terms of seasonality of symptom onset, the results indicate that seasonality remains in the male bipolar group, but other groups have no seasonal trend.
  
  
  CONCLUSIONS
  This provides further evidence that systems mediating the entrainment of biological rhythms to the environment may be more pronounced in BPAD than in schizoaffective disorder and schizophrenia. These results may help facilitate the preparedness of mental heath services for patients at different times of the year.
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Karen T
authors.initials: KT
authors.lastname: Hallam
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Michael
authors.initials: M
authors.lastname: Berk
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Linda F
authors.initials: LF
authors.lastname: Kader
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Phillipe
authors.initials: P
authors.lastname: Conus
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Nellie C
authors.initials: NC
authors.lastname: Lucas
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Melissa
authors.initials: M
authors.lastname: Hasty
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Craig M
authors.initials: CM
authors.lastname: Macneil
authors.affiliation: 1Mania Research Group, ORYGEN Youth Health.
authors.forename: Patrick D
authors.initials: PD
authors.lastname: McGorry