A curious link between inattention and hoarding could lead to new ADHD therapies

A few years ago, Sharon Morein-Zamir was sitting with colleagues at a conference when the conversation turned to hoarding.

It’s a subject Morein-Zamir researches as part of her work as an associate professor at Anglia Ruskin University in England. Many people who are diagnosed with hoarding disorder suspect they also have undiagnosed ADHD. Morein-Zamir had a thought — do people with ADHD have an issue with hoarding? She decided to find out.

Anecdotally, there seems to be a connection. On Reddit people with ADHD discuss their hoarding tendencies, while people with ADHD on TikTok talk about their propensity for storing their stuff in piles or throwing it together in “doom boxes.” But anecdotes are not facts and these stories lack the nuance needed for a diagnosis: There’s a difference between hoarding and hoarding tendencies, and the evidence for a connection between hoarding and ADHD is limited.

Morein-Zamir’s work marks a significant change: Her team found people with ADHD are significantly more likely to report hoarding tendencies compared to the general population. In a group of 88 people diagnosed with ADHD, 19 percent displayed clinically significant features of hoarding (clinically significant refers to whether a trait meets the criteria for a medical diagnosis). In fact, all the people with ADHD in the study displayed more hoarding tendencies compared to the study’s control groups, which numbered 310 people in total, all without ADHD.

Just 2 percent of one control group of 90 people without ADHD displayed hoarding symptoms, while 3 percent of the other control group of 220 people without ADHD showed signs of hoarding.

It’s important to think of hoarding-related behaviors on a continuum, explains Morein-Zamir, with hoarding behavior moving from a manageable problem to a disruption to daily life. While not everyone with ADHD reported hoarding tendencies that could be called excessive, people with ADHD were more likely to be somewhere on this continuum compared to people without ADHD.

The link between ADHD and hoarding — Hoarding disorder is characterized by having a persistent difficulty in getting rid of excessive amounts of items. These items contribute to clutter and the inability to let them go can cause a person clinically significant levels of distress and problems completing everyday tasks. Hoarding typically emerges in late adolescence and gets worse over time. Most people who have a hoarding problem never seek help or treatment: Overall, more women with hoarding tendencies will seek help than men, so some experts think men may be especially underserved when it comes to getting care.

Most of what we know about hoarding stems from research concerning people diagnosed with OCD. Hoarding used to be lumped under the OCD label in the Diagnostic and Statistical Manual of Mental Disorders (DSM), but in 2013 hoarding disorder was officially recognized as its own diagnosis in the DSM-5 to wide agreement. Now, many scientists recognize that some people with hoarding disorder also show symptoms similar to those seen in people with ADHD.

Research on ADHD and hoarding is a new area of study, so for now scientists must look to research on people diagnosed with hoarding disorder to try and understand what might prompt this behavior, Morein-Zamir says.

Inattention was the only significant statistical predictor of hoarding severity in her study’s ADHD group. Inattention can mean a host of things, Morein-Zamir explains, including difficulties with organization, forgetfulness, procrastination, and being easily distracted to a degree that impairs everyday life. When inattention is compounded with depression and anxiety, hoarding becomes even more likely.

“While most people have some degree of issue with these things at times, in ADHD it is more severe, more prolonged, and has this impact,” Morein-Zamir says.

She notes that people with hoarding disorder tend to have problems with executive functioning, which overlaps with some of the problems experienced in ADHD. Executive functioning refers to the high-level cognitive skills used to govern memory, flexible thinking, and self-control.

The takeaway — There’s already so much misinformation on ADHD online, a rise that coincides with over-prescribed ADHD meds, and a rise in self-diagnosis. While people should feel empowered to manage their mental health in a way that is safe and sustainable, there is a risk in pathologizing regular behavior. Speak to a mental health professional and determine how disruptive your tendencies are to your life before you diagnose yourself with anything.

And importantly, there is a difference between having a hoarding disorder, displaying hoarding-like tendencies, and being generally messy.

There’s also a need for more research on the subject — and more awareness.

“My personal experience has been that the link between inattention and hoarding is well known in the [hoarding disorder] domain — to the degree where some claimed the findings from the study were obvious — even though it hasn’t been assessed in adult ADHD directly before,” Morein-Zamir says.

“The possibility of a link does not seem to be well known at all in the ADHD research or clinical community at all — to the degree where it is met with skepticism and dismissiveness,” she adds.

She hopes both research communities realize their common ground and collaborate.

Morein-Zamir also hopes her research encourages clinicians to talk to people with ADHD about hoarding. While not all people with ADHD will hoard, talking about it can act as an informal screening to prevent symptoms from worsening. Ultimately, people with hoarding disorder are also dealing with an often debilitating stigma — frank and calm conversations are essential to break the stigma down and open up access to care.