20 August Today's term from psychology is Delusions.

Delusions are false or irrational beliefs maintained despite clear evidence to the contrary. The key to interpreting delusions as a symptom of mental disorder is that there must be significant contrary evidence.

If a person has delusional disorder, they may appear to behave normally, except for their specific delusion. And in some cases, their delusions may even seem believable, at least at first glance.

Delusions are considered "bizarre" if they are clearly implausible and even people from the same cultural group can't understand them. An example of a bizarre delusion is when an individual believes that his or her internal organs have been replaced with someone else's without leaving any wounds or scars.

This condition is actually quite rare, with an estimated 0.2 percent of people experiencing it at some point in their lifetime.

There are several different types of delusional disorders, and each type captures a particular theme within a person's delusions.

Erotomanic: An individual believes that a person, usually of higher social standing, is in love with him or her.

Grandiose: An individual believes that he or she has some great but unrecognized talent or insight, a special identity, knowledge, power, self-worth, or relationship with someone famous or with God.

Jealous: An individual believes that his or her partner has been unfaithful.

Persecutory: An individual believes that he or she is being cheated, spied on, drugged, followed, slandered, or somehow mistreated.

Somatic: An individual believes that he or she is experiencing physical sensations or bodily dysfunctions, such as foul odors or insects crawling on or under the skin, or is suffering from a general medical condition or defect.

Mixed: An individual exhibits delusions that are characterized by more than one of the above types, but no one theme dominates.

Unspecified: An individual's delusions do not fall into the described categories or cannot be clearly determined.