My sibling recently confided in me that they have tried some king of psychedelic mushrooms and that they regularly inhale marijuana vapor (or something to that effect) and showed me where they keep their device. They are 15 years old. Can I report this to my parents? Or throw away the device? Thank you Rav.
It is nice to see that you are so concerned about your sibling.
Throwing out the device is not a good idea, because the same way your sibling got a hold of the money to buy the first device without asking anyone, he will find the money to buy another one, especially if he is addicted to it. The only effect that will happen due to your throwing out the device is that you will have totally lost the trust of your sibling, which is very detrimental, because now you will not be able to help him.
Regarding telling your parents about it, that is a tricky question, and it depends on your situation, and who your parents are. If your parents are the type that will try to deal with the situation incorrectly, it might make it worse and then they should not be told. Instead maybe try speaking to his Rebbi in yeshiva, the Rov of the shul, or someone else who is capable of dealing with this issue correctly, without over reacting or acting emotionally and on impulse. However if your parents will handle the situation correctly you can tell them, but again whatever is done has to be done smartly, and in a way that will not cause your sibling to realize that you said anything to anyone. Because then he will feel that you broke his trust.
You should have much hatzlocha.