Obsessive-Compulsive Personality Disorder (OCPD):
People with OCPD are often overly punctual, orderly, perfectionistic, excessively devoted to work, preoccupied with details and rules, rigid, and many insist that others abide by their way of doing things. Some of these traits may occur in people with OCD, however, they aren’t related to the typical obsessions and compulsions characteristic of OCD. It is important that OCD and OCPD not be confused with each other because their may differ.
Substance abuse, sexual addiction, compulsive overeating and compulsive gambling:
People with these problems act compulsively but not in response to an obsession. With each of these issues, the person derives pleasure and/or a high from engaging in their activity of choice. In contrast, when engaging in compulsions, a person with OCD simply experiences relief from their obsession and/or anxiety.
Delusional thoughts:
Delusional thoughts are thoughts not grounded in reality but are believed to be true by the person experiencing them. Paranoid delusions are common in paranoid disorders and schizophrenia. People with OCD are generally able to recognize that their obsessive thoughts are irrational even if they behave in response to them. In the past, people with OCD were misdiagnosed with schizophrenia because some of their thoughts and beliefs resembled delusions.
Baer, L. (2000). Getting Control: Overcoming Your Obsessions and Compulsions. New York: Plume.