I keep on getting this question, why did Declan leave Degrassi?

For anyone that does not know who Declan is he is the twin sister of Fiona Coyne. Played by actor Landon Liboiron, who is now starring on a show on FOX called Terra Nova. He was consitered a regular in seasons 9 and 10. ( a regular means was in almost every episode.) So he came to Degrassi as the diplomats son and was included in action with the break-up between Peter and Mia. Declan's cousin named Victoria an addict gave Peter drugs. That made them break-up. Declan's first small relationships included never before seen extras named Sophie and Trish. His first real relationship was with Holly J. Sinclair.
The reason Declan left the show is because after several break-ups, Declan was accused of something with Holly J.. And decided to leave and graduate at Vanderbulit.