All right, well, you better be prepared for a long but very interesting story.
In 2011, I became friends with this guy when I started 6th grade (and thus, middle school) when the school year started early in August. He and I were officially friends until our freshman year in high school in 2015, but there were many bumps along the way.
I never knew him terribly well for a while, and he never visited my house until my twelfth birthday in February 2012, and even then, he didn't visit for another year after that, meaning our friendship was never really big until 2013. That being said, a lot did happen between 2011 and 2015, particularly starting in 2012.
He is mentally ill (I still know him as he goes to my high school and we've gone to school together ever since we combined for the middle schools in 2011, although I'm moving to Alabama soon), and that is one thing that he was never terribly honest with me about during the early months of our friendship in 2011, although I could start noticing it by December that year. By the spring of 2012, a series of incidents began that lasted until spring 2015.
In April 2012, there was an incident while we were still in 6th grade (this was just a month before the school year ended) where, because I had become good friends with someone else in our gifted class by that point (he and I were in the same gifted class during 6th grade year and the first couple of months of 7th grade year in 2011 and 2012, but by October of 2012, he was pulled out by his mom to improve his grades in other classes by being learning strategies, which was basically a study hall), and apparently, he had gotten jealous and wanted to receive attention. So, while I was using one of the computers in class and was wearing headphones (which our teacher required us to wear when using the computer so sound wouldn't blare out), he lifted the part of the headphones covering my left ear and screamed in it. Apparently, the principal was in an adjacent room meeting with some 7th grade teachers, so since there was a connecting door between the rooms, she rushed in and asked my teacher who made the noise, and she asked if he knew the kid (mentioning his name, of course). The principled replied saying that she wished she didn't know him...
In October 2012, while we had been working on a project in my gifted class that year for the past month, he constantly bugged and annoyed me making me unable to get any work done. This caused me to get very far behind on it and have to turn it in late, which extremely angered my parents, also because my grades had been going down at the time with the start of a new nine week period, resulting in a one-hour time limit to be allowed to use electronics from my mom (down from two that she had set that previous May) and constant criticism and insults from my dad.
In December 2012, he acted crazy at the house of two of my friends (twin brothers) while we met up for our Christmas break. This scared their mother so much, and it was even worse in June of 2013 when he came to their thirteenth birthday party and literally went insane the whole time, doing inappropriate and sometimes even violent actions. Apparently, within a couple of months, around either August or September that year, he said that the reason he acted that way in June was because he had not taken a medication that he usually takes daily for his illness. He was apparently wary of telling us this information because he thought we'd judge him for it, although it didn't change our view of him at all. However, it did make us more cautious of any incidents that took place after September 2013.
In December 2013, there was a Christmas dance for the 7th and 8th graders at my school that I wasn't planning on going to. I was in 8th grade by this time, and I hadn't gone to the one the previous year, but he insisted I come as he apparently had liked it the previous year and when he had gone to it then, he went with his girlfriend, but she had broken up with him that previous October. I ended up going (particularly because I was pressured by my mom), and he kept following his ex-girlfriend and one of our other friends (who went with her) and basically acted like a complete idiot. That wasn't my day, and it made me feel like I shouldn't have even been at that dance in the first place.
In May 2014, he told a girl that I had liked for several months that I liked her as "revenge" for something I did that apparently made him angry (told his ex-girlfriend that he was a liar, as he lied to her about me). He had known since that previous March that I had liked this girl in question. Anyways, on our 8th grade Class Day, which marked our last day of middle school, she ended up rejecting me, and that happened just four days before my grandpa passed away, which made that one of the worst points in my life.
In September 2014, just a month into our freshman year of high school, he found out that my parents along with those of the same friend I mentioned that he treated horribly that previous December weren't big fans of him. This made him angry and act crazy, and caused great strife among us, almost ending the friendship (which it probably should have then).
In March 2015, I finally ended the friendship after he acted crazy for days. Unfortunately, that action apparently put him at a breaking point for the rest of the month on into April and May.
So, yeah, I only continued the friendship partly so that he wouldn't go crazy like he eventually did in the spring of 2015, but yeah, not exactly a healthy friendship I had there.
Sorry this was so long BTW.