People with Attention-Deficit/Hyperactivity Disorder (ADHD) are significantly more likely to also exhibit hoarding behaviours, which can have a serious impact on their quality of life, finds a new study.

The study, published in the Journal of Psychiatric Research, found that almost one in five people with ADHD exhibited clinically significant levels of hoarding, indicating there could be a hidden population of adults struggling with hoarding and its consequences. "Hoarding Disorder is much more than simply collecting too many possessions. People with diagnosed Hoarding Disorder have filled their living areas with so many items and clutter that it impacts their day-to-day functioning leading to a poorer quality of life, anxiety, and depression," said researcher Sharon Morein from the Anglia Ruskin University (ARU), the UK.

Hoarding disorder is a recognised condition that involves excessive accumulation, difficulties discarding and excessive clutter. The disorder can lead to distress or difficulties in everyday life and can contribute to depression and anxiety. For the study, the research team recruited 88 participants from an adult ADHD clinic run by the Cambridge and Peterborough NHS Foundation Trust.

The study found that 19 per cent of this ADHD group displayed clinically significant hoarding symptoms, were on average in their 30s, and there was an equal gender split. Amongst the remaining 81 per cent, the researchers found greater hoarding severity, but not to a degree that significantly impaired their lives, compared to the study's control group.

The researchers asked the same questions, about ADHD symptoms and impulsivity, levels of hoarding and clutter, obsessive-compulsive severity, perfectionism, depression and anxiety, and everyday function, on a closely-matched group of 90 adults from the general population, without an ADHD diagnosis, and found only 2 per cent of this control group exhibited clinically significant hoarding symptoms. They then replicated this with a larger online sample of 220 UK adults to see if similar patterns were found, and similarly, only 3 per cent of this group exhibited symptoms.