Okay, so I have a MC who gets addicted to sleeping pills. As time passes he takes progressively more and more (without killing himself) until he is addicted. My question specifically is what would be negative side effects of an addiction like this? Are there even any side effects other than drowsiness? I'm thinking something along the line of slight shaking, crankiness / irritability, fatigue, possibly stomach problems. I don't need a specific drug, I just need to know if these are realistic, if they aren't what would be realistic? Really, so long as the main effect or known use is as a sleep aid it doesn't matter.