Seasonality of births in schizophrenia and bipolar disorder: a review of the literature

  title={Seasonality of births in schizophrenia and bipolar disorder: a review of the literature},
  author={E Fuller Torrey and Judy L. Miller and Robert R. Rawlings and Robert H. Yolken},
  journal={Schizophrenia Research},

Season of birth in schizophrenia and affective psychoses in Western Australia 1916±61

While age-incidence effects had no impact on the distribution of risk, an artefactual increase in January births due to routine imputation of missing birth dates is found, analogous to northern hemisphere trends.

Epidemiological comparison of schizophrenia and bipolar disorder

  • E. Torrey
  • Psychology, Medicine
    Schizophrenia Research
  • 1999

Winter birth excess in schizophrenia and in non-schizophrenic psychosis: Sex and birth-cohort differences

Decreasing seasonal variation of births in schizophrenia

The intensity of the factor causing the seasonal variation of births in schizophrenia may be decreasing, and urban birth may be emerging as a risk factor for schizophrenia in Finland, as elsewhere.

Seasonality of birth in seasonal affective disorder.

Besides genetic factors, season of birth or seasonal changes in environmental factors also could influence the development of SAD, and birth effects seem to be dependent on the symptom profile of the patients, but further studies are needed to elucidate the underlying mechanisms of these observations.

Seasonality of births in affective disorder in an Irish population

Excess in the spring and deficit in the autumn in birth rates of male schizophrenic patients in Italy: Potential role of perinatal risk factors

  • G. BersaniD. Pucci P. Pancheri
  • Psychology, Medicine
    The journal of maternal-fetal & neonatal medicine : the official journal of the European Association of Perinatal Medicine, the Federation of Asia and Oceania Perinatal Societies, the International Society of Perinatal Obstetricians
  • 2006
The findings serve to strengthen the existing hypotheses that schizophrenia is related to environmental factors acting on the development of the central nervous system intrauterinely.


The results confirm the association between summer birth in the Northern Hemisphere and deficit as opposed to nondeficit schizophrenia and the existence of a different risk factor for the two groups suggests a difference in etiology and pathophysiology.



Mental Disorder and Season of Birth—A Southern Hemisphere Study

It is hypothesized that the relationship between schizophrenia and winter birth is consequent upon a greater sensitivity of schizophrenics to those physiological factors which determine conception in the general population.

Season of birth: schizophrenia and bipolar disorder.

Evidence suggests that the seasonal effect is associated with a subgroup of schizophrenics who have early onset of psychosis, less genetic loading than other schizophrenics, and better prognosis.

The Brain Damage Hypothesis of the Seasonality of Births in Schizophrenia and Major Affective Disorders: Evidence from Computerised Tomography

Compared with schizophrenics born during the remainder of the year, those born between December and April, particularly in cases lacking a family history of schizophrenia, showed increased chances for ventricular enlargement, but not for cortical atrophy, suggesting the brain-damaging effect played by perinatal seasonal factors has both a disease and an anatomical specificity.

Season of birth and schizophrenia: Sex difference

Seasons of birth and subtypes of schizophrenia

This work examined the seasons of birth of 472 patients carrying the diagnosis of schizophrenia, and studied the gender and paranoid vs nonparanoid subtypes of this subject group.

Mental Disorder and Season of Birth

A decade-by-decade comparison of years of birth of schizophrenic patients in Sweden with the general population found a very significant excess of the patients had been born in the months January to March.

Excess seasonality of births among patients with schizophrenia and seasonal ovopathy.

The results show a winter excess of births among Dutch schizophrenia patients, even when statistical artifacts are avoided, and that the SPrOO hypothesis might be an explanation for this excess.

Season of Birth and Neuropsychological Impairment in Schizophrenia

There was no evidence of elevated rates of neuropsychological dysfunction among winter-born patients on any measure, and the results suggest no strong season of birth relationship with Neuropsychological impairment in a reasonably large, research diagnosed sample of schizophrenic patients.

Season of birth and Schneider-oriented diagnosis of affective disorder.

The present German study, carried out on affective disorder diagnosed in a strongly Kurt Schneider-oriented clinic, found that there was no significant overrepresentation of births in the winter or early months of the year for all types of affective Disorder, neurotic as well as psychotic.