Birth season has a significant impact on your risk of developing mood disorders, scientists have found.
People born at certain times of year may have a greater chance of developing certain types of affective temperaments, which in turn can lead to mood disorders (affective disorders).
Researchers from Budapest, Hungary, found that birth season is linked with temperament.
"Biochemical studies have shown that the season in which you are born has an influence on certain monoamine neurotransmitters, such as dopamine and serotonin, which is detectable even in adult life," said Assistant Professor Xenia Gonda, lead researcher of the study.
"This led us to believe that birth season may have a longer-lasting effect. Our work looked at over 400 subjects and matched their birth season to personality types in later life.
"Basically, it seems that when you are born may increase or decrease your chance of developing certain mood disorders," Gonda added.
"We can't yet say anything about the mechanisms involved. What we are now looking at is to see if there are genetic markers which are related to season of birth and mood disorder," Gonda said.
The group found that cyclothymic temperament (characterised by rapid, frequent swings between sad and cheerful moods), is significantly higher in those born in the summer, in comparison with those born in the winter.
Hyperthymic temperament - a tendency to be excessively positive - was significantly higher in those born in spring and summer.
Those born in the winter were significantly less prone to irritable temperament than those born at other times of the year.
Those born in autumn show a significantly lower tendency to depressive temperament than those born in winter.
The study will be presented at the European College of Neuropsychopharmacology Congress here.