People can use a car to act out their suicidal urges and drive at high speed into a solid object. This is then an expression of suicidal urges. However there are others who will drive such that their own and others lives are put at risk and some times people are killed. This is different as it is an expression of homicidal – suicidal urges.
Forget the whole testing thing and start the slow process of rebuilding the lines of communication. Hopefully it wont be too late and there are not too many deep scars left on both parent and teenager, such that a reconciliation is impossible.
However there is quite a sizeable group (most people) who use drugs and alcohol in a non problematic way. They use drugs and alcohol such that their life script is not advanced and their relationships are not damaged in any significant way.
Full contact in relationships is something that many humans seek but at the same time can be frightening. It seems safe to say that the natural human condition is to have quite a strong ambivalence about emotional intimacy in relationship.
If one has the opportunity it is pertinent to ask the parents about the good child in the family. The one who is not making any noise can be the one in most pain.
A man will usually use a woman as a trophy because of his own insecurities and magical thinking as this diagram shows. He has doubts about his own worth and OKness.