Astrologers have long tried to convince us that our month of birth holds secrets about our individual personalities and ultimate fate in life.

The jury’s still out on the dependability of the zodiac, but there is scientific and statistical evidence that suggests your birth month can influence success or health.

A study published by the Canadian Medical Association Journal on March 5 found that children born in December were 39 per cent more likely to be treated with medication for attention deficit hyperactivity disorder (ADHD) compared to children with a January birthday.

Here are some other areas that seem to be affected by your birth month.

Sports

In the opening chapter of his 2008 book Outliers, journalist Malcolm Gladwell pointed out that the majority of elite Canadian hockey players were born in the first few months of the year. The reason, he deduced, is minor leagues determine eligibility by calendar year, which means kids born on Jan. 1 compete with kids born on Dec. 31 in the same year. The older kids are typically bigger and more mature, and thus stand out to coaches and scouts, who do their best to nurture their talents.

Stephen Leavitt and Stephen J. Dubner, authors of the bestselling Freakonomics series of books, noted this trend in a 2006 New York Times column, but focused on international soccer. Like the minor-hockey leagues, the cutoff date for FIFA — the world governing body for soccer — is Jan. 1.

However, FIFA only introduced the Jan. 1 cutoff date in 1997. Of those players in 2006 World Cup action born after 1979 — and thus affected by the new cutoff date — the percentage who were born in January, February and March (32.4 per cent) outweighed those born in April-May-June (25.2), July-Aug.-Sept. (21.5) and Oct.-Nov.-Dec. (21).

Prior to 1997, the FIFA cutoff was typically in August, although it varied from country to country. Of those players in 2006 World Cup action born before 1979, the highest percentage were born in July-Aug.-Sept (31.7), while the lowest percentage were born in Jan.-Feb.-March (20).

Learning

Similar trends seem to be at play in the educational system. In Canada, the cutoff date for children starting school is Dec. 31, which means they can be in the same class as students born in January the same year.

A 2011 study of B.C. students who entered kindergarten in 1995 found that compared to those born in January, kids with December birthdays were 12 to 15 per cent less likely to meet reading and numeracy standards in the elementary grades and 12 per cent less likely to graduate.

In Britain, the school cutoff date is Aug. 31, which means kids learn with classmates born in September of the previous year. In a 2011 study, researchers at Britain’s Institute for Fiscal Studies reported that kids born in August have less confidence in their academic abilities and are less likely to attend top universities.

Health

Research done by British scientists suggests a child’s birth month can affect his or her susceptibility to disease. According to the theory, the determining factor is the mother’s exposure to sunlight during pregnancy — the sun’s rays contain vitamin D, which regulates thousands of genes during development.

The study suggested that babies born between March and June are more prone to certain pathologies and disorders, including Parkinson's, diabetes, glaucoma, narcolepsy, autism and multiple sclerosis.

If it all comes down to the amount of mom’s tanning time, then it appears being born in October or November is best. Unless, you live in the Southern Hemisphere, that is, where spring is indeed the preferable period.