OCD is classified in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) as an anxiety disorder. Based on DSM-IV, it says that for the person who suffers from OCD can be diagnosed to have the presence of either obsession or compulsion.
There are the 4 criteria for obsession based on DSM-IV:
Recurrent and persistent thoughts, impulses, or images are experienced at some time during the disturbance as intrusive and inappropriate and cause marked anxiety and distress. Persons with this disorder recognize the pathologic quality of these unwanted thoughts (such as fears of hurting their children) and would not act on them, but the thoughts are very disturbing and difficult to discuss with others.
The thoughts, impulses, or images are not simply excessive worries about real-life problems.
The person attempts to suppress or ignore such thoughts, impulses, or images or to neutralize them with some other thought or action.
The person recognizes that the obsessional thoughts, impulses, or images are a product of his or her own mind (not imposed from without, as in thought insertion).
Whereas for compulsion it can be based on 2 criteria through DSM-IV:
An individual performs repetitive behaviours (e.g., hand washing, ordering, checking) or mental acts (eg, praying, counting, repeating words silently) in response to an obsession or according to rules that must be applied rigidly. The behaviours are not a result of the direct physiologic effects of a substance or a general medical condition.
· The behaviours or mental acts are aimed at preventing or reducing distress or preventing some dreaded event or situation. However, these behaviours or mental acts either are not connected in a way that could realistically neutralize or prevent whatever they are meant to address or they are clearly excessive.