Schizophrenia is more widespread among individuals born during the winter months—especially in January, according to a new, large study. Furthermore, the month in which a baby is born greatly affects his or her eyesight and eating habits and also influences birth defects and even personality later in life.
Past research has implied that the birth month of a child affects its mental health in later stages of life.
“For example, maternal infections — a mother may be more likely to have the flu over the winter. Does this increase risk?” said researcher Sreeram Ramagopalan, an epidemiologist at Queen Mary University of London.
“Or diet. Depending on the season, certain foods – fruits, vegetables — are more or less available, and this may impact on the developing baby. Or another key candidate is vitamin D, which is related to sunshine exposure. During the winter, with a lack of sunshine, moms tend to be very deficient in vitamin D.”
The study included almost 58,000 individuals with schizophrenia, bipolar disorder or recurrent depression as well as over 29 million people from England’s general population.
Mental disorders appeared season-based. Specifically, schizophrenia and bipolar disorder had statistically higher peaks in January and significant lows in July, August and September. Depression had an almost significant May peak and a significant November deficit.
“This result is further confirmation of seasonal variations in births of those later diagnosed with mental diseases,” said William Grant at the Sunlight, Nutrition and Health Research Center at San Francisco, who did not take part in this research.
“This implicates conditions during pregnancy. The two most likely factors are vitamin D status and temperature,” said Grant.
Source: Queen Mary University of London