Related Experiment Video
Updated: Aug 29, 2026

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
What causes seasonality of birth in schizophrenia?
Mamoru Tochigi1, Yuji Okazaki, Nobumasa Kato
1Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
Abstract:
An excess of winter-spring births (and/or a decrease of summer births) has consistently been observed in schizophrenia (SCZ). This observation may provide a significant clue about the causes of the disease if specific factors which cause the phenomenon can be determined. This paper reviews several studies which investigated factors correlated with this observation in SCZ, in an attempt to determine which factors more likely cause the seasonality. Among the candidates of the factors are meteorological variables (such as ambient temperature), several infections, maternal hormones, sperm quality, nutrition and external toxins. A variation of procreation might also have an effect. Among the factors, the most extensively studied are temperature and viral infections. Some of them have appeared promising, but further studies are definitely required. Several challenges, including complicated correlations of the factors and determination of the susceptible period during pregnancy, need to be overcome. Comparisons of the data from areas and cohorts with different patterns of the candidate factors may be helpful. Animal studies may also help investigate the molecular and physiological mechanisms of the phenomenon.
Related Concept Videos
Biological Causes of Schizophrenia
Genetic Factors in Schizophrenia
The genetic basis of schizophrenia is strongly supported by family and twin studies.
Psychological and Sociocultural Causes of Schizophrenia
Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within the...
Schizophrenia
Bipolar Disorder
Negative and Cognitive Symptoms of Schizophrenia
Negative Symptoms
Negative symptoms of schizophrenia manifest as deficits in normal emotional and behavioral functioning, profoundly impacting daily life. Individuals with schizophrenia often display a flat affect, characterized by a near-total absence of emotional expression,...

