The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, (DSM-5, in medical parlance) is a handbook, if you will, to assist in making diagnostic judgments in cases of mental disorders. The manual classifies conditions and provides diagnostic criteria in addition to medical codes from the International Classification of Diseases (ICD-9). The DSM-5 released in 2013 includes both ICD-9-CM codes which are currently in use, and also features the relevant ICD-10-CM codes to prepare clinicians for the code-set transition later this year.
Although the behavioral health sector will not experience the vast increase in codes as, say, the field of orthopedics, mental health professionals still need to be familiar with the coding intricacies of these diagnoses and the changes posed by ICD-10. Not only is the actual code different in ICD-10 but the guidelines for coding certain diagnoses may have also changed. For example, ICD-10 includes combined codes for alcohol use and its related conditions such as hallucinations or withdrawal. Understanding the changes and proper education of clinicians and staff will minimize revenue disruptions.
http://www.govhealthit.com/blog/how-get-your-behavioral-health-codes-right