An excellent article by Mothers Against Meth-Amphetamine goes into considerable depth about the importance of treating chemical dependency and co-existing mental disorders at the same time.  The article begins with a nice overview of Methamphetamine addiction.  The article goes on to psychiatric disorders that commonly co-occur with Methamphetamine addiction, such as PTSD, depression, anxiety, bipolar disorder, ADHD, dementia, and psychosis.  To read this article in its entirety, click here.