Need some tips on how others handle lying | ADHD Information

I know that it is largely due to his impulsivity, but I am tired of dealing with my grandson's lies.    He's 12 years old and I'm afraid that the lying will only get worse and lead him down the wrong path in life.   Nothing I do seems to work.  Any ideas?
I taught preschool for years and found that the reason children lie, was because they did not want to get in trouble. This is what I did, what some would not do but felt was the only solution. When my student started to tell a lie, I would give them two choices. 1. Tell the truth and you will NOT get in trouble for it, or 2. Lie, and you will get a time out and your favorite toys taken away. They ALWAYS chose the truth! I have done the same with my son who is 7 yrs old. He speeks freely with me about his day and if he had to pull  a card. He tells me on his own! I thank him for telling me and being truthful and then talk about how he can improve things for the next day and sometimes I tell him Im disappointed (some times) but I always end with thank you for telling me. This may not be an approach that many might take. It is a positive re-inforcement type of disclipline. Kids need to know you are Not against them. This may open up some amazing communication. Try it, who knows..it may just work. You DO have to be strict about it and follow through. I do remember having to put a child on time out etc for lying but they did NOT do it the next time. I ground for an entire weekend day. No media, no going outside except for
the backyard, no friends over, no phone. That's a zero tolerance issue for
me, impulsive or not. No excuses for lying.My daughter, ADHD, has a huge problem with lying. Yep,
she says she doesn't want to get in trouble. But in our
house you pretty much only get in trouble WHEN you lie.
Our son lied but got the rule right away. He is ADHD too.
But my daughter has been a tough one to crack.
I reinforce the rules all the time. But, and here is the
tricky part, if they tell you the truth - don't punish
them. Talk to them and move on. If we punish when they
tell the truth when they did something wrong - it's a
mixed message.
It takes time but it works. I also take my daughter to
see a therapist (she is adopted from foster care) and she
works on that with her as well. Big improvements.

Good luck!I have the same problem with my 13 year old daughter.  Just the other day I noticed a picture frame on the mantle just didn't look right.  When I picked it up it fell apart in my hands.  When I asked her about it she said "it just fell".  When I pointed out that it has sat on that mantle for years with no problems she finally admitted she bumped it and that's how it broke. She got in trouble for the lie and the cover up.  I explained that if she had just told us she bumped it and it broke we wouldn't be nearly as mad as we are finding out it was covered up and then she lies about it.  This is a small example of the lies she automatically tells.  We have other kids who tell small lies like normal kids do, but my daughter lies about EVERYTHING.  Its so frustrating!