DeGrandis says he’s struggled from depression and anxiety, which he believes may be linked to his inability to let certain things go. In getting to know other HSAM study participants, he’s learned this is a common theme.

“I consider myself lucky in that I’ve had a pretty good life, so I have a lot of happy, warm and fuzzy memories I can think back on,” he says. “But I do tend to dwell on things longer than the average person, and when something painful does happen, like a break-up or the loss of a family member, I don’t forget those feelings.”

Research also suggests that people with HSAM tend to have obsessive traits.