Asthma and attention deficit hyperactivity disorder (ADHD) specialists have indicated a potential link between what month a person is born in and their risk for either disorder, but sufficient evidence has not been lacking. Scientists from Columbia University have developed an algorithm capable of explaining the relationship between the month a person is born and their risk for disease. Long story short, people born in May are at a lower risk for chronic diseases compared to those born in October.

“This data could help scientists uncover new disease risk factors," Dr. Nicholas Tatonetti, the study’s senior author and an assistant professor of biomedical informatics at Columbia University Medical Center (CUMC) and Columbia's Data Science Institute, said in a statement. "It's important not to get overly nervous about these results, because even though we found significant associations, the overall disease risk is not that great. The risk related to birth month is relatively minor when compared to more influential variables like diet and exercise."

A person’s risk for developing asthma was significantly higher if they were born in July and October. When it came to ADHD, one out of every 675 diagnoses were associated with someone who was born in New York in November. One unsettling finding from the study had to do with the relationship between birth month and nine different types of heart disease, the leading cause of death in the United States. People born in March face the highest risk for atrial fibrillation, congestive heart failure, and mitral valve disorder.

Findings from this study out of Columbia University are in line with research performed by researchers from Austria, Denmark, and Sweden. For example, the association between asthma risk and July/October birthdays is similar to a Danish study that discovered a link between asthma risk and May/August birthdays (Sunlight levels in May and August in Denmark are similar to those in New York in July and October). Just like this study, a previous study carried out in Sweden found that ADHD rates peak in children born in November.