ADHD is basically the overactive absorption of dopamine. Dopamine is the hormone that basically activates neural pathways in stronger form, which is the "motivation" feeling to go do things.

If you have ADHD, you can have a lot of secondary effects from your inability to motivate you to go do things.

ADHD medication, which is basically meth, basically prevents the reuptake dopamine, meaning that it says bound to the neurons. You fundamentally get the tool to go and actually do things. But a tool is not the solution without knowing how to use it, for that you need additional support, which is most commonly is therapy.