Hoarders' Brains Overwhelmed by Decisions
Imaging Study Points to Disorder Distinct From Obsessive-Compulsive Disorder
Aug. 6, 2012 -- Two brain regions go on high alert when hoarders must decide whether to keep something they own or throw it away.
In a new study in Archives of General Psychiatry, brain images of those regions show that hoarders respond quite differently when making such decisions than people with obsessive compulsive disorder and people without any mental disorder.
"That brain network goes into hyperdrive, starts freaking out," says researcher David Tolin, PhD, a psychologist at the Institute of Living in Hartford, Conn. "The task seems to overload the network."
When it comes to their own possessions, says Tolin, the decision-making process for hoarders becomes very difficult, even painful, so they avoid it. And so, stuff keeps piling up.
"It's very common, and it can be very sad," he says.
To help see what happens in hoarders' brains at the moment of decision-making, Tolin and his colleagues recruited 107 adults for their experiment. Forty-three of them were hoarders. Thirty-one had been diagnosed with obsessive compulsive disorder (OCD). The remaining 33 were healthy.
Each was told to bring in a load of paper items such as junk mail from around their houses. While an fMRI machine took real-time images of their brains, the recruits were asked to decide whether to keep or throw away each item.
They were also asked to decide the fate of stuff that did not belong to them. Tolin brought in a bag of his own junk mail, which he had collected for the previous six months. The participants were shown their own stuff and Tolin's in random order during sessions that lasted about an hour.
The brains of the hoarders showed little response when confronted with Tolin's credit card offers, Netflix coupons, and other junk. Asked about their own, similar belongings, the hoarders' brains -- specifically the anterior cingulate cortex and the insula -- both showed abnormal activity.
"The only real difference between the stuff was the name on the address label," says Tolin. "And the affected brain regions really flip flopped on the basis of ownership."
Tolin says those regions are known to play a big role in assigning importance and relevance to objects. For someone with arachnophobia, for example, seeing a spider would activate those areas in a big way. Hoarders have the same type of brain reaction, the study shows. Their brains assign undue importance and relevance to things that most people would consider junk.
Hoarding Distinct From OCD
The other participants in the study showed no such reaction to the decision-making process. Although that may not be surprising for the healthy group, it is a telling detail regarding OCD. Tolin says that until recently, hoarding has been considered a component or sub-type of OCD. The fact that different brain regions are at play in the two groups is evidence that the two disorders are distinct.