Differences between Obsessive Compulsive Disorder & Delusional Disorders?

I'm not sure what I have. I have been diagnosed with OCD in the past but lately it seems like I'm believing I've done horrible things & I haven't. I don't know if I have something else wrong with me. Can someone please tell me the differences between these two disorders? I hear about the same things on message boards with other people. Like people with OCD thinking they ran someone over & didn't or they have hurt a child & didn't, I do things like that but wouldn't that technically be a Delusional Disorder? If not what exactly makes these two different?

Delusional disorder is a psychiatric diagnosis denoting a psychotic mental illness that involves holding one or more non-bizarre delusions in the absence of any other significant psychopathology (signs or symptoms of mental illness). In particular, a person with delusional disorder has never met any other criteria for schizophrenia and does not have any marked hallucinations, although tactile (touch) or olfactory (smell) hallucinations may be present if they are related to the theme of the delusion.


A person with delusional disorder can be quite functional and does not tend to show any odd or bizarre behavior except as a direct result of the delusional belief. "Despite the encapsulation of the delusional system and the relative sparing of the personality, the patient's way of life is likely to become more and more overwhelmed by the dominating effect of the abnormal beliefs". (Munro, 1999)

The term paranoia was previously used in psychiatry to denote what is now called 'delusional disorder'. The modern psychiatric use of the word paranoia is subtly different but now rarely refers to this specific diagnosis.

Obsessive-compulsive disorder (OCD) is a psychiatric anxiety disorder most commonly characterized by a subject's obsessive, distressing, intrusive thoughts and related compulsions (tasks or "rituals") which attempt to neutralize the obsessions.

The phrase "obsessive-compulsive" has worked its way into the wider English lexicon, and is often used in an offhand manner to describe someone who is meticulous or absorbed in a cause (see "anal retentive"). Such casual references should not be confused with obsessive-compulsive disorder; see clinomorphism. It is also important to distinguish OCD from other types of anxiety, including the routine tension and stress that appear throughout life. Although these signs are often present in OCD, a person who shows signs of infatuation or fixation with a subject/object, or displays traits such as perfectionism, does not necessarily have OCD, a specific and well-defined condition.

A delusion is a deeply deeply engrained belief- like a belief in God. You don't necessarily believe what you're thinking. You just have the "what-ifs". See?