New Research — ADHD, medication and task reward: What does this research imply about appropriate adjustments for homework?
The battle to complete homework is a familiar one to parents of a child with ADHD. After a long day at school, with medication waning, it can be hard for a child to get excited about a 30 minute maths sheet - even if maths is a strength. Parents become increasingly inventive, frustrated and sometimes just despairing: how can I get my child to just pay attention for long enough to get this done?
The A in ADHD is attention, and so it follows that we try to restore attention. Medication is prescribed to fix it. School targets are written to build it. Homework is set on the expectation that a supported, medicated child can sustain it. A study published in Cell in December 2025 challenges that assumption directly. What the researchers found matters hugely for every parent at the kitchen table at seven in the evening with an unfinished worksheet.
Their finding is deceptively simple. Stimulant medication did not change the brain's core attention networks. It acted on two other systems: networks that regulate alertness and wakefulness, and networks tied to reward, drive and motivation. Better focus is real, but it is actually the by-product. What the researchers propose is that stimulants raise the perceived value of routine tasks, with maths homework as their own example, so the child stops abandoning them for something else. That is task reward. The brain puts a price on every task. When the price is too low, effort collapses.
Researchers at Washington University in St Louis looked at brain scans from 5,795 children aged 8 to 11. The scans were taken while the children were resting, not doing a task. Children who had taken stimulant medication that day were compared with children who had not. The results were the same whether or not a child had ADHD. A small check with five adults without ADHD showed the same pattern. Medication changed the parts of the brain that control alertness and reward. It did not change the part that controls attention. It makes effort more available.
Here are two examples to consider. A nine-year-old builds Lego for two hours without a break, then cannot finish ten subtraction questions. An eleven-year-old recites every Premier League table from memory, then cannot write one paragraph on a set text. Neither child has a broken attention system. Both concentrate well when the task pays back. The difficulty lies in the value the brain assigns to the task. Stimulants appear to raise that value.
The study has clear limits. Children were scanned at rest, not while doing schoolwork. The design was observational, not a randomised trial. The researchers state that the ABCD sample was not large enough in each group to compare specific medications or ADHD subtypes. The adult check involved five people. The sample was American. The study describes what stimulants do, not what ADHD is. It tested no homework strategy.
Benjamin Kay, a child neurologist and co-author of the study, described the tasks children cannot focus on as the ones they find unrewarding. Fidgeting is a search for stimulation the task fails to supply. Raise the reward and the search ends.These research findings will come as no surprise to parents, but they are important because they change the narrative around what we can, and can’t, do to support task completion for low reward tasks.
Homework is the lowest-reward task in a child's day. It is set by an absent teacher. It arrives at the end of the day. Feedback comes days later, if at all. Much of it is repetitive practice. Many stimulant formulations are timed to cover the school day, so the reward support has often faded by the evening. Homework therefore lands when task value is lowest, the child is most tired, and medication is wearing off. Late homework then cuts into sleep, and the next day's medication may conceal the deficit.
Homework is a demand designed by schools. Homework policies assume every child assigns the same value to the same task. Sanctions for incomplete homework, such as detentions or lost break times, treat a reward-processing difference as a choice. Support plans focus on attention strategies, such as movement breaks and chunking, and rarely address the value of the task itself. The failure sits in task design and policy, not in the child.
What does this mean for homework?
Homework works better when it is short and has variety. The same worksheet given daily with different problems is a task reward turn off.
Immediate feedback is likely to increase task reward.
An adult working alongside the child may raise the value of the task. This may be why a child won’t attempt it without your help.
At school, homework for children with ADHD needs lower volume, less repetition and faster feedback.
Non-completion should not carry sanctions: this is neurodivergence, not challenging behaviour.
The most important adjustment I can propose is that for pupils with ADHD, homework should be completed within the school day, while medication is active. This is a legitimate adjustment. Homework that drags on into the night falls outside the hours medication covers, and disrupts already vulnerable sleep patterns.
There is a secondary finding in the study about medication and sleep which backs this up, but is beyond the scope of this blog. Just know that while children who had slept too little performed better after taking a stimulant, there is a noted difference between looking rested and being rested. The researchers warn that stimulants may imitate the benefits of sleep while leaving the long-term damage of chronic sleep loss untouched. This matters to child well being, and should matter to school. Homework needs to be reconsidered through the lens of appropriate accommodations that value overall well being as much as academic achievement.
Stimulants appear to work by raising arousal and task reward, not by repairing attention. The open question is whether schools will redesign homework around task reward, or continue to set work that only medication makes bearable.
Source
Kay, B. P., et al. (2025). Stimulant medications affect arousal and reward, not attention networks. Cell, 188(26), 7529–7545. https://doi.org/10.1016/j.cell.2025.11.039