Certain types of schizophrenia may be linked to summer birth

Patients with deficit schizophrenia, a subtype of schizophrenia characterized by “negative” symptoms, such as blunted speech and expression, lack of emotional response, and apathy, are more likely to have been born in the summer months, according to an article in the October issue of The Archives of General Psychiatry, one of the JAMA/Archives journals.

According to the article, winter birth was reported to be a risk factor for schizophrenia in 1929. Clinical aspects of patients with schizophrenia born in the winter include paranoia and a more benign course of illness. Additionally, the clinical features associated with winter birth are different from patients with deficit schizophrenia, defined by the presence of negative symptoms, including inability to experience pleasure, lack of interest in socializing, speech deficits, blunted emotional response, poor eye contact, and more severe course of illness. Nondeficit schizophrenia is characterized by symptoms including hallucinations, incoherent thinking, and prominent delusions.

Erick Messias, M.D., M.P.H., of The Johns Hopkins University, Baltimore, Md., and colleagues analyzed published and unpublished data from the northern hemisphere on studies of season of birth with information on schizophrenia and its subtype- deficit or nondeficit. A total of 1,594 patients were included in the nine studies examined.

“This pooled analysis of data from six countries in the northern hemisphere showed a significant association between deficit schizophrenia and summer birth,” write the authors. “Information on month of birth only, as opposed to day of birth, was available across studies, and our analyses found an increase in June/July. However, it is likely that a more seasonal pattern would have been apparent with more detailed information.”

“Our results support the concept of a double dissociation in deficit vs. nondeficit schizophrenia and the risk factor of season of birth, with the deficit group associated with summer birth and the nondeficit group with winter birth. This difference strongly suggests differences in etiology between the two groups,” the researchers write.

“Seasonal variations in infectious agents, sunlight exposure and vitamin D, and the availability of nutrients have been proposed as possible explanations for the seasonality of births in schizophrenia. However, to date, no specific agent has been identified,” conclude the authors.

Media Contact

Bill Seiler EurekAlert!

More Information:

http://www.jama.org

All latest news from the category: Health and Medicine

This subject area encompasses research and studies in the field of human medicine.

Among the wide-ranging list of topics covered here are anesthesiology, anatomy, surgery, human genetics, hygiene and environmental medicine, internal medicine, neurology, pharmacology, physiology, urology and dental medicine.

Back to home

Comments (0)

Write a comment

Newest articles

Lighting up the future

New multidisciplinary research from the University of St Andrews could lead to more efficient televisions, computer screens and lighting. Researchers at the Organic Semiconductor Centre in the School of Physics and…

Researchers crack sugarcane’s complex genetic code

Sweet success: Scientists created a highly accurate reference genome for one of the most important modern crops and found a rare example of how genes confer disease resistance in plants….

Evolution of the most powerful ocean current on Earth

The Antarctic Circumpolar Current plays an important part in global overturning circulation, the exchange of heat and CO2 between the ocean and atmosphere, and the stability of Antarctica’s ice sheets….

Partners & Sponsors