People with ADHD are often disorganized and considered "messy". This stems not directly from the ADHD but as a result of multiple other symptoms. ADHD brains tend to get overwhelmed very easily. This overwhelm is caused by the inability to properly prioritize tasks as well as time blindness. Getting overwhelmed can cause a person with ADHD to procrastinate doing things such as cleaning up a mess. Procrastination leads to more clutter. More clutter leads to being overwhelmed. Overwhelm leads to procrastination. And the vicious cycle repeats.