The core symptom of ADHD is that it is especially difficult to sustain focused attention on cognitive tasks that a person finds boring, repetitive, and unappealing. If they don’t procrastinate till the deadline, which creates a sense of panic that motivates them, their mind wanders quickly, they become distracted as they read a paragraph and recall poorly what they read.
The same may happen with boring lectures without visual aids, especially when not the night before the test.
Paperwork, applications, taxes, balancing a checkbook, making and sticking to a budget are usually more difficult.
Those with ADHD may or may not also be disorganized, impulsive, hyperactive, or restless and fidgety.
There is usually a sense of underachievement and that others with less capability are passing them by. This can lead to disillusionment and low self-esteem.