Studies across different countries have given credence to the connection between schizophrenia and winter births. In 2012, scientists performed the largest study around this connection ever conducted in England, which involved 57,971 patients and also explored bipolar affective disorder and recurrent depressive disorder. (BPD seemed linked to winter birth, whereas RDD correlated with late spring births.) Though no definitive causal link has been described that can explain this association, researchers have speculated that it may have to do with vitamin D deficiency.
Share the knowledge!
Key Facts In This Video
If you were born in the summer, research suggests you're more likely to be a smoker or shortsighted. 00:34
Increased exposure to sunlight in women who get pregnant in the summer may raise the likelihood of left-handedness and schizophrenia in their children. 01:22
The seasonal birth effect is only visible when looking at large populations, and no causal links between birth dates and characteristics have yet been found. 02:43