The Neanderthal DNA you didn’t know you have is likely causing you some problems.

A new study by the University of Washington and Vanderbilt University has found that the small of amount of Neanderthal DNA that most people have is linked to a wide variety of less-than-enjoyable conditions, “including depression, nicotine addiction, heart attacks, corns and calluses.”

The Seattle Times reports that the study examined the DNA of 28,000 participants. People of Eurasian descent typically can trace 1-4% of their genetic material to Neanderthal ancestors. That 1-4% accounts “for less than 2 percent of an individual’s total risk for any particular condition.”

The percentages might seem insignificant, but researchers say the link is real:

“‘I would describe it as a pervasive but modest effect,’ said UW geneticist Joshua Akey, a co-author of the study. ‘You can blame your Neanderthal ancestry a little — but not too much — for whatever range of afflictions you have.’”

Ancient Homo sapiens, our ancestors, intermingled with Neanderthals about 50,000 years ago when migrating out of Africa. The researchers say that their hybrid offspring must have had some genetic advantages or their DNA would have died out.  Unfortunately, an advantageous trait like good blood clotting back then is linked to a higher risk of stroke now.

Akey hopes that “a better understanding of genetic variability and its sources can aid the quest for cures and treatments.”

The study is a fascinating insight into our past, although likely not much comfort for anybody suffering from these afflictions.