Help with my 5 year old boy!

I am the mother of an amazing 5 year old boy who, lately, has been lying (in order to gain something, like lying to my boyfriend to say I said he could have candy, or lying to get out of trouble) and VERY argumentative lately. He has started back talking and having an attitude, and he has developed selective hearing. I've tried time outs, taking privileges away (no TV for the day, time out, even spanking) with no results.Side note: He has shown signs recently of ADHD, like having a LOT of energy, unable to sit still, unable to focus on things, etc. Oftentimes, his fidgeting will take his attention away from other things that require his focus, like homework or chores. I plan on speaking to his doctor about this at his next check up in a couple of weeks, but nothing has been confirmed yet, so I don't want to assume his behavior could be partially caused by this, but I think it's a possibility.I feel like I'm doing the same thing over and over with the same result. His behavior isn't changing, and I'm tired of it. Can someone give me some advice on a different way of handling this? I'm exasperated as hell. via /r/Parenting http://ift.tt/2gZi4Zm