Winter birth

How is winter birth related to risk for bipolar disorder?

Researchers have observed the existence of high and low prevalence (total number of cases) and incidence (number of new cases during a specified time frame) pockets for some psychiatric disorders, with rates varying depending on season of birth. These may be related to variances in temperature, precipitation, and sun exposure, however, the underlying mechanisms involved are largely unknown.

What is the evidence regarding winter birth as a risk factor for bipolar disorder?

Moderate to low quality evidence suggests there may a greater risk of affective psychoses in people who were born in late winter in the northern hemisphere (January to April).

Affective psychosis is a broad diagnostic category which includes bipolar disorder.

June 2020

Last updated at: 12:53 am, 25th June 2020
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