Teens with ADHD are typically more impulsive than same aged peers, though it is less common among girls (they tend to be dreamy, disorganized, and underachieve in school). Among girls who display a more 'hyperactive' type of ADHD, unfortunate teen behaviors can include shoplifting, cutting class, tying cigarettes/alcohol and making other foolish decisions without thinking of the consequences. Teens almost invariably know full well the consequences of their choices when you ask them, but report that they "just didn't think about it" when they made their mistake.
Researcher Russell Barkley has noted that adolescents with ADHD are often about 3 years behind peers in terms of their maturity and judgment. Your daughter may be enjoying 17 year old freedoms with about 14 year old maturity. I usually recommend to parents of teens with hyperactive/impulsive ADHD that they provide the level of supervision they would expect to give to a child a few years younger than the child's chronological age.
You will need to help your daughter learn to make wise choices. The lying is really annoying I am sure, but my greater concern is that her lying is preventing you from being able to protect her from herself. I recommend you implement a behavior contract with her that lays out reasonable expectations as well as rewards and privileges to be earned. Teems often respond well to behavioral contracts, particularly if they are fair and contain lots of 'goodies' for them to get. You will need to be prepared to follow through with consequences, and stand firm about granting privileges once she has fulfilled her side of the bargain.
The book The Kazdin Method by Dr. Alan Kazdin has an excellent chapter on how to negotiate a behavior plan with teens. I would encourage you to seek behavior psychotherapy if you have the time and the means, as you want to make sure that your intervention does not fail or have loopholes. The book How to Talk so Teens Will Listen and Listen so Teens will Talk by Adele Faber has a lot of great information about how to communicate effectively with her and handle problems like lying. You may also wish to consult a psychiatrist to discuss medication options if her behavior is putting her in danger.
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