This study aims to evaluate the efficacy of MET (or MI), relative to standard (intake/orientation/evaluation) procedures at participating CTPs, in enhancing treatment engagement and retention as well as in reducing substance use. It will also evaluate the durability of MET (or MI) relative to standard treatment at CTPs through a 3 month follow-up. Secondary aims of this study are to explore patient characteristics associated with outcome, to evaluate the ability of clinicians at the CTPs to learn and effectively implement MET/MI techniques, and to conduct process analyses which will assess and evaluate multiple aspects of this treatment approach.

**The data files and related study documentation were updated on December 13, 2006 to make the following changes.  Please update your files if you have already downloaded any study data/documentation:

1. A prefix was added to the deidentified patient identifier (DEIDNUM) to make analyses across trials easier.  The prefix is the trial number.

2. Formulas and derivation logic rules to the comments field in define.xml were included where possible.  Most variables are simple translations/mappings from the data source and do not require a comment.

3. Some of the graphical elements in the PDF CRF annotation were not appearing when Acrobat versions other than Acrobat 5 were used.   We have updated the PDF CRF files to alleviate this problem entirely.

**The data files and related study documentation were updated on May 8, 2007 in order to increase compliance with SDTM current standards.  Please update your files if you have already downloaded any study data/documentation.  Any analyses currently underway should not be affected with these updates.