Hi Robin,
Thank you for your question! It is recommended to avoid alcohol while taking Adderall. Taking both together may cause central nervous system depression, such as slowed breathing rate, sluggishness, delayed response time, etc. If your son insists on drinking, he may want to avoid taking Adderall on the days that he will be drinking. Or he may want to drink just a little bit at a time to see how the Adderall and alcohol together will affect him. You can read more about Adderall at this site. Above all, tell him to be safe and not to push the limits!
Casey