You can't choose when you were born, which can sometimes be a pain in the butt in terms of birthday party planning. And now there's one more reason why that fact is very inconvenient.

The season you were born in has an affect on your mood, according to a new study presented at the European College of CNP Congress in Berlin. A group of Hungarian researchers looked at more than 400 subjects and matched them to their personality traits later in their lives.

"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," lead researcher Xenia Gonda said in a statement. "Basically, it seems that when you are born may increase or decrease your chance of developing certain mood disorders."

The researchers found that cyclothymic temperament, which is characterized by mood swings between happy and sad temperaments, is higher in summer babies rather than those born in winter. Hyperthymic temperament, or having a very positive disposition, was significantly higher among those born in the spring and summer. Winter babies were less likely to be irritable than those born at other times of the year, but they were more likely than autumn babies to develop depressive tendencies.

Unfortunately, the researchers aren't able to say yet exactly why this is the case. "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 also said in a statement.

Past studies have shown that the weather, your environment, music and even food can influence your mood. The great thing about all of that is you're generally in control of all of those things, except the weather of course. Curse you, rainy days and Mondays that always get me down! But if you're feeling irritable and it's because you were born in winter, there's really not much you can do to change that. Kind of depressing, right?