Why hoarding happens

Twin studies show that hoarding is partly inherited. Brain scans show that people who hoard can respond differently when deciding about their own things.

Stressful events, changes in relationships and hard experiences in childhood are all linked with hoarding. For some people they seem to start it. For others they make it worse.

Whatever starts hoarding, a loop often keeps it going. Letting go feels painful, so decisions get put off. The relief teaches the brain that putting off works, so next time is even harder.

Many people who hoard feel their past is stored in their things. Letting go of a ticket stub or a child’s drawing can feel like losing that moment forever.

This was one of the three sides of attachment most strongly linked with hoarding, even after taking low mood and worry into account.

Some people describe their things as a source of comfort and safety. When the world feels uncertain, possessions can feel steady and reliable.

Researchers call one version of this “insecure object attachment”. It means feeling anxious about losing things, a bit like worrying about losing a person. This side was strongly linked with hoarding.

Seeing human-like qualities in things is called anthropomorphism. Most of us do it a little, like naming a car. Research has linked doing it more strongly with saving more and picking up more free things.

If an object feels like it has feelings, throwing it away can feel cruel. That makes sense of a lot of distress that looks puzzling from the outside.

For some people, belongings feel like an extension of their identity. Books might stand for the person you hope to be, and craft supplies for the creative self you value.

Letting go can then feel like giving up part of yourself. Therapy often helps people find other ways to express who they are.

Many people see the potential in things that others overlook. A broken lamp could be fixed. A jar could hold buttons. Throwing it away can feel wasteful or even wrong.

Intolerance of uncertainty means finding the unknown very uncomfortable and wanting to avoid it. It has been linked with hoarding. Keeping everything can feel like a way to avoid every possible regret.

In a 2026 study of 41 adults in a group program, this discomfort with uncertainty went down after treatment. People whose uncertainty eased the most tended to improve the most.

In a brain-scan study of 107 adults, the brain changes seen in people who hoard were linked to how indecisive they felt and to “not just right” feelings while deciding.

Wanting things to be perfect can also play a part. If a choice must be perfect, not choosing can feel safer.

Research links hoarding with differences in attention, organizing, planning and memory. Someone may see every item as unique, so it can’t go in a group with others.

In older adults who hoard, harder times with planning, working memory and switching between tasks were strongly linked with how severe hoarding was.

In one clinic study, about 32% of adults with ADHD also met criteria for hoarding. Inattention can mean sorting starts but never finishes, and new things keep arriving.

In a 2012 study, people decided in real time whether to keep or shred papers. In people who hoard, two areas called the anterior cingulate and the insula were less active than usual for other people’s papers.

But for their own papers, these areas became much more active than in other groups. These areas help us sense what matters and manage strong feelings.

A 2005 study looked at 86 people with brain injuries and no earlier history of collecting. Thirteen began collecting so much it disrupted their lives, and all had damage to the same front-middle part of the brain.

The researchers think this area normally helps balance our natural urge to gather things against what makes sense in our surroundings.

Hoarding can show up as part of several brain and mental health conditions, including dementia. Most early brain research came from people with brain injury, dementia or OCD.

A Swedish study of thousands of twins found genes explained 41% of hoarding differences at 15, 31% at 18 and 29% at ages 20 to 28. In boys at 15, genes played a bigger part than in girls.

In teen girls, the shared family environment also mattered. The researchers say causes may shift as people grow.

In a study of 82 older adults who hoard, having at least one parent with hoarding tendencies was linked with higher hoarding levels earlier in life.

This can be partly genes and partly what we learn at home. Both are reasons for understanding, never blame.

A 2021 review of 39 studies found links between cold or controlling family experiences in childhood and more severe hoarding later on.

The review also says these links are not unique to hoarding. They show up in other struggles too, and the research is still limited.

In a survey of 751 adults who hoard, changes in relationships were often linked in time with hoarding starting or getting worse. Most people described hoarding as lasting a long time.

Grief after a death is one of the possible triggers listed by the NHS. Keeping a loved one’s things can feel like keeping them close.

In the same survey, violence from other people was also often linked in time with hoarding starting or getting worse. Another study found that the more traumatic events people had lived through, the more severe their hoarding tended to be.

When people feel unsafe with others, things can feel like a safer place to put trust and care.

A 2021 study compared people who hoard with people living with anxiety or PTSD. Most kinds of hard events were no more common in hoarding, except crime-related events.

In another study, people whose hoarding began in early childhood were less likely to link it to a stressful event. So for some, hoarding seems to begin without any clear trigger.

Getting something new can bring comfort or excitement. Over time, buying or collecting can become a way to manage hard feelings.

Therapy for hoarding helps people stay with uncomfortable feelings for a little longer, in small steps. Over time, the brain learns the feeling will pass without keeping the item.

If people have been unreliable or hurtful, objects can feel like a safer place for love and trust. They are always there and never reject you.

Researchers have suggested that attachment to things may sometimes make up for feeling less secure with people.

A 2026 review of 13 studies found a clear link between hoarding and loneliness. It isn’t yet clear which comes first.

Shame about the home can stop people inviting others in. Fewer visitors can then mean things fill the space people once did.

What treatment can include

• Building motivation by linking change to your own values
• Gently questioning beliefs about what things mean
• Practising sorting and letting go in small steps
• Skills for organizing, problem solving and deciding
• Steps to limit bringing new things in

Hoarding is not about laziness or weak will. It grows from real emotions, real brain differences and real life events.

Asking “What does this item mean to you?” opens doors. Asking “Why can’t you just throw it out?” usually closes them.

CBT for hoarding has the best research support, and many people make real gains in safety, space and stress. Change often takes time and may not be complete.

The Resource Directory at hoarding.iocdf.org lists therapists, clinics, treatment programs and support groups. You can search by zip code or city.

The IOCDF also lists over 200 support groups for hoarding, OCD and related struggles, for both individuals and families.

In the UK, the NHS suggests seeing a GP, who can refer you to a mental health specialist. Elsewhere, start with a family doctor.

If you need to talk to someone now, findahelpline.com lists free, confidential helplines in many countries.