Attention deficit causes difficulties with various tasks and learning to read is certainly one of them.
Struggles to keep focused some tasks, but not others
Tends to be fidgety and easily distracted
An apparent excess of energy
Impulsive responses to stimulae rather than considered reactions
It was a huge surprise to me when I found out that the drugs for attention deficit are based on cocaine. It reflected how completely I misunderstood the nature of the problem.
The reason a stimulant like cocaine is effective is that it raises the activity of the pre-frontal lobe, allowing that area of the brain to effectively "take control" of the rest of the brain. Someone with attention deficit is lacking the energy needed in that area to enforce focus across the rest of the brain. As a result their brain tends to respond to any sensory stimulation and they flit from one point of focus to another.
Learning to read demands a lot of energy and a sustained focus for around 10 minutes per day. So attention deficit makes progress extremely hard to achieve.
There are two possible avenues with this. You can either alleviate the attention deficit or create a way to help the person learn to read with the attention deficit.
There is lots of information available on ways to alleviate an attention deficit. So that avenue should definitely be explored, ideally without doses of cocaine!
Our focus here is on how to help someone progress despite an attention deficit.
The first step is to keep the lessons very short but regular. And they should also be at a time when the learner is relatively fresh. So a 10-minute lesson, run daily in the morning, is the ideal.
Then the lesson should be as entertaining and engaging as possible. The easiest way to achieve that is to use games or very good stories or factual material of interest to the learner. A good measure of whether your lessons are good is how well someone with attention deficit responds to them. If they lose focus, you are being boring!