I am really enjoying this story but I am a little puzzled by all the reviewers who say how accurate the details are. As I'd say it's enjoyable despite the details.
In particular, the odds of getting an appointment on turning up are close to none. Beside the fact that a teacher definitely couldn't do it without parental permission.
Other details - Snape only sees Harry for one lesson. Even accounting for less stringent diagnosis back then, this would not happen. One adult does not constitute multiple settings. Generally, professionals require informants from multiple places over a period of time, especially for children. (Adults can be diagnosed faster.)
Also, there is no way 3 months would be prescribed at once. There are health checks (particularly cardiac) which must be done before taking stimulants and then careful monitoring (generally weekly in the UK) of pulse, heart rate, side effects, etc. There is also a slow taper up to the final dose.
Author's Response: Thank you for your review! I know the odds of getting a doctor's appointment out of the blue is extremely rare, and yes, the other details are valid as well. They were all things I considered when I was writing this, and still things I am debating fixing now. As it is a fanfic, I went with the cliched 'handwaving magic of the author' to explain how it all happens so quickly, because it's honestly less about Harry seeing a doctor and getting a prescription than it is about Harry and Snape's relationship. Most of the reviewers talking about accuracy are talking about the relationships, and how Harry and Snape act. I will also admit, since I'm not from the UK, I don't know how many of the medical practices differ from where I live, which is also why I was extremely vague on that area.
So, thank you again for the review, and I'm rather sorry that the details aren't up to par but still hope that you enjoy the story regardless.