system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does everyone react differently to certain types of medication (like stimulants for ADHD), and why do the results and side effects vary so much?
gpt
Short answer is because our bodies and brains have lots of differences. We're all different heights and colors, have differently shaped heads and legs, have different strengths and weaknesses, have different innate tolerances to alcohol, etc...

Point being that our genetics allow for a wide variety of different traits. This means that we don't all respond to medication the same way.

There's also the fact that not all conditions are made the same. A good example of this is antidepressants. These medications don't work for all depressed individuals because they only target a specific mechanism that causes depression. If the cause of your depression is slightly different, this medication can have little to no effect.