How the birth season can trigger mood disorders

The risk of developing mood disorders is impacted by the season in which you are born in, a research showed.

People born at certain times of year may have a greater chance of developing certain types of affective temperaments which, in turn, could lead to mood disorders (affective disorders).

"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," said Xenia Gonda, assistant professor from the department of clinical and theoretical mental health at the Semmelweis University in Budapest, Hungary.

The team looked at over 400 participants and matched their birth season to personality types in later life.

The group found that cyclothymic temperament (characterised by rapid, frequent swings between sad and cheerful moods), is significantly higher in those born during summer in comparison with those born during winter.

"Hyperthymic temperament - a tendency to be excessively positive - were significantly higher in those born in spring and summer," Gonda added.

Those born during winter were significantly less prone to irritable temperament than those born at other times of the year.

While those born during autumn show a significantly lower tendency to depressive temperament than those born during winter, the researchers noted.

"Temperaments are not disorders but biologically-driven behavioural and emotional trends. Although both genetic and environmental factors are involved in one's temperament, now we know that the season at birth plays a role too," concluded professor Eduard Vieta from the European College of Neuropsychopharmacology (CNP).

This work was presented at the European College of CNP Congress in Berlin recently.