Dysfunctional

Abnormality (or dysfunctional behavior), in the vivid sense of something deviating from the normal (c.f. Norm (social)) or differing from the typical (such as an ), is a subjectively defined behavioral characteristic, assigned to those with rare or dysfunctional conditions. Behavior is considered abnormal when it is atypical, out of the ordinary, causes some kind of impairment, or consists of undesirable behavior. Often what is abnormal, or what is not abnormal, is determined by an individual's culture. The definition of what abnormal behavior is a contentious issue in abnormal psychology. It is an assumption that abnormal behavior is a disorder that has a physical cause, specifically that it is related to the physical structure of the brain. A diagnosis of a mental disorder describes a patient who has a medical condition and the doctor makes a judgment that the patient is exhibiting abnormal behavior. The distinction being that mental disorders describe processes, not people.

There are five main criteria of abnormality. They are

According to "Essentials of Abnormal Psychology" by Durand and Barlow, abnormal behaviors are "actions that are unexpected and often evaluated negatively because they differ from typical or usual behavior".

A common approach to defining abnormality is a Multi-Criteria approach, where all definitions of abnormality are used to determine whether an individuals behavior is abnormal. For example, if an individual is engaging in a particular behavior that is preventing them from 'functioning', breaks a social norm and is statistically infrequent, then psychologists would be prepared to define this individual's behavior as abnormal. A good example of an abnormal behavior assessed by a multi-criteria approach is depression: it is commonly seen as a deviation from ideal mental stability, it often stops the individual from 'functioning' a normal life, and, though it is a relatively common mental disorder, it is still statistically infrequent. Most people do not experience significant major depressive disorder in their lifetime.

...
Wikipedia