Why are dual diagnosis treatment centers better? First, dual diagnosis rehab treatment centers are rehabs that provide treatment got both psychiatric and substance abuse problems. Most alcoholics and drug addicts suffer from some kind of mood disorder, like depression, bi-polar, anxiety or ADD. So when they use and abuse drugs and or alcohol it is a form of “self-medication” to relieve their discomfort. That having been said, unless a treatment properly addresses any and all co-occurring psychiatric problems, the person is at a very high risk of relapse. The best drug rehabs offer a good dual diagnosis program.