There has been much debate about the usefulness of a subjective text that is used for scientific deduction in the diagnosis and treatment of mental ailments. However, the proof, as they say, is in the pudding. If the DSM wasn’t at least acceptably accurate and had a high rate of success with patients then it wouldn’t be used. Unfortunately, despite its usefulness, it can still be an extremely hard text to fully understand if you don’t know at least the basics of how to use it.
First, the DSM uses a categorical system to help the user identify certain ailments correctly. The categories are hypothetical cases that, if matched closely, can effectively be used to diagnose and, later, treat the patient. While none of the categories will match individual patients perfectly, they will offer you a way to identify what the patient is going through more easily.
The text also uses a multi-axis system that allows one to find the proper category of ailment more easily. These axes are split up into five sections and each section is devoted to a particular problem that may exist in the patient. Axis I, and Axis II will end up being the most valuable for the practicing psychologist/psychiatrist as these are the two axes that offer the most relevant information on mental illnesses and disorders.
Finally, it should be noted that while the Diagnostic and Statistical Manual of Mental Disorders is a text to allow the diagnosis and treatment of someone. It shouldn’t be used by anyone that has not received the extensive training it takes to use the DSM correctly; it should also not be applied, even in clinical settings, as a blanket/catch all solution to a problem as other issues may exist.