A lot of people have trouble with clutter. The mail piles up, the kids' toys occupy more space than we'd like, half-finished projects gather dust on a table. That's normal for the most part. It's not hoarding.

You've probably seen the TV show "Hoarders," which shows people who live with clutter at a more extreme level. What's going on in their heads? And more importantly, what's at the root of the problem?

Hoarding is the consistent difficulty a person may have discarding or giving away possessions, regardless of if they have inherent value or not. Hoarding can be detrimental not only to the hoarder but to others who live in the house.

For hoarders, it’s the sheer quantity of their stuff that sets them apart from other people. They can hoard anything from newspapers and magazines to cardboard boxes, food and clothing.

"Many experts think of hoarding as a type of compulsive behavior,” explains Dr. Raphi Wald, a licensed psychologist in South Florida. This can mean compulsively buying things, acquiring free items or searching for a perfect or unique item.

"It is an inner discomfort that can only be relieved by performing some type of ritualistic act. There is a strong biological component to most compulsive behaviors," says Wald. "There is a specific part of our brain that is responsible for helping us stay still and not have to take action in all situations. The volume of this brain structure is often different in people that demonstrate more extreme compulsions.”

Driven by anxiety

living room of hoarder Hoarding disorder compels people to compulsively cling to items that eventually clog up their homes and take over their lives. (Photo: Shadwwulf at English Wikipedia/Wikimedia Commons)

In 2012, researchers led by David Tolin at the Yale School of Medicine studied hoarders' responses to facing an everyday decision: keeping or discarding their junk mail. The scientists found this decision prompted an abnormally high level of activity in two areas of a hoarder's brain — the anterior cingulate cortex and the left insulate cortex. The more activated the response, the higher the level of anxiety and indecision.

Basically, their brains went into overdrive, much like what happens when a smoker or a drug addict is faced with quitting. By keeping their things, hoarders feel a sense of relief, which soothes their anxiety — and the cycle repeats.

It’s still not clear what causes hoarding, but there are some commonalties linking people with a hoarding problem. “Like many psychological disorders, a biological predisposition toward obsessive-compulsive disorder can be triggered by any stress, such as a major injury, or even worry about everyday life stressors like money," Wald says.

When clutter becomes hoarding and starts affecting someone's day-to-day quality of life, then you know it’s a serious problem.

It should be noted that hoarding is different from collecting. Collectors store or display their possessions in an organized fashion and take care to preserve their worth. Also, they're discerning when it comes to adding something to their collection. Hoarders will take home many things, store them haphazardly and let them get dusty.