Babies born in the summer are much more likely to suffer from mood swings when they grow up while those born in the winter are less likely to become irritable adults, scientists claim.
Researchers studied 400 people and matched their personality type to when in the year they were born, UK daily The Telegraph reported on Sunday.
According to the report, scientists have claimed that people born at certain times of the year have a far greater chance of developing certain types of temperaments, which can lead to mood disorders.
The scientists, from Budapest, said this was because the seasons had an influence on certain monoamine neurotransmitters, such as dopamine and serotonin, which control mood, however more research was needed to find out why.
They discovered that the number of people with a “cyclothymic” temperament, characterised by rapid, frequent swings between sad and cheerful moods, was significantly higher in those born in the summer.
Those with a hyperthymic temperament, a tendency to be excessively positive, was significantly higher among those born in the spring and summer.
The study also found that those born in the autumn were less likely to be depressive, while those born in winter were less likely to be irritable.
Lead researcher, assistant professor Xenia Gonda, said: “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. 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.
Professor 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”.
The study was presented at the annual conference of the European College of Neuropsychopharmacology (ECNP) in Berlin, Germany, on Sunday.
Professor Eduard Vieta, from the ECNP, said: “Although both genetic and environmental factors are involved in one’s temperament, now we know that the season at birth plays a role too.
“And the finding of “high mood” tendency (hyperthymic temperament) for those born in summer is quite intriguing.”
