Addiction to ADHD meds

M husband was diagnosed about a year ago and was prescribed Adderall for his ADHD.  It really did make a difference, but he has been struggling with the addictive nature of the medicine.  I've found out tonight he has been abusing it for the past months.  Feel like 4 steps forward, 20 backward.  Does anyone else know anything about this and what did you do?  I mean if its a syndrome and helps, is that just a side note that it's addictive?  Help!  I am shocked and really disappointed right now.  Thanks.