Educational reference
About this symptom
Difficulty sustaining attention describes trouble holding focus on a task over time, particularly where the task is repetitive, effortful or offers little immediate interest.
It is easy to misread. Attention in ADHD is not uniformly poor: many people concentrate intensely, sometimes for hours, on activities they find genuinely engaging. That contrast is often taken as evidence that the difficulty is a matter of choice or motivation. It is better understood as difficulty regulating where attention goes, rather than an absence of attention.
In practice it shows up as losing the thread partway through reading, drifting during conversations or meetings, starting tasks and moving to others before finishing, and needing to re-read or re-do work.
Attention is affected by many things besides ADHD, including poor sleep, anxiety, depression, pain, thyroid conditions, and stressful circumstances. Difficulty that is new, rather than longstanding, is more likely to have another explanation and is worth discussing with a health professional.