What Is Abnormal?

Abnormal psychology is the study of abnormal mental processes and behavior. Abnormal is defined as “not normal,” but this definition isn't sufficient in the field of psychology. For one thing, normal is a relative term. For instance, what you consider to be abnormal behavior may be considered normal by your neighbor. Society also has its own standards for normal. A mental health professional must be able to define abnormal behavior and then determine when abnormal behavior constitutes a mental disorder. Not an easy task.

Determining Abnormal Behavior

There are several factors a mental health professional must take into account when trying to determine whether a person's behavior is abnormal. For nearly any type of behavior that you might consider, there is what is called a normal range. People may rank either higher or lower than an average set point, but everything that falls within this range is still considered normal. It is when a behavior lies too far outside of this standard range that it may start to be viewed as abnormal or maladaptive.

Another factor is whether the behavior is distressing to the person. The behavior is only abnormal, however, if the person suffers severe emotional distress or other consequences as a result of the behavior. All people suffer distress from time to time, but this is considered normal. When the behavior becomes extreme or happens on a frequent basis, it is considered abnormal.

One factor is whether the behavior violates cultural standards. Every society has its own set of norms deemed acceptable, and you are expected to conform to those societal norms. Subcultures also have norms; for example, within society in general, wearing extremely baggy pants and bandanas might be seen as abnormal. However, it would not only be considered normal, but would be almost required, in particular subcultures. A behavior that does not conform to the norm of the person's culture is considered statistically abnormal and undesirable. Another factor is whether the behavior is harmful or maladaptive. If the behavior impedes your ability to adjust to the demands of everyday life, it is considered maladaptive. Of course, a behavior that is dangerous and could lead to the harming of oneself or others is considered abnormal.

Other factors determine whether the behavior is irrational, unpredictable, or inexplicable. In these cases, others cannot understand a person's behavior. For instance, someone with anorexia may look as thin as a rail to an outsider, but she believes she looks fat, so she restricts her eating and exercises excessively. This is an irrational behavior that most people cannot understand. Sometimes behavior takes place for no apparent reason. For instance, a person who shouts obscenities at a complete stranger for no apparent reason is considered to be acting erratically. Such behavior is inexplicable and unpredictable and is therefore abnormal.

Making a Diagnosis

Making a diagnosis of mental disorder isn't as easy as just identifying abnormal behavior. Abnormal behavior can be a symptom of a mental disorder, but it does not automatically lead to the existence of a mental disorder. Certainly everyone has behaved irrationally before, but that doesn't mean we all have a mental disorder. These are isolated incidents of a temporary state.

A mental health professional must look at abnormal behavior in terms of length of time and severity. If two or more factors of abnormal behavior apply to a person's behavior, then that warrants a closer look. A person is diagnosed with a mental disorder if the abnormal behavior occurs frequently over an extended period of time and it disrupts a person's normal day-to-day living.

Classifying Mental Disorders

To help identify and diagnose mental disorders, mental health professionals have developed a classification system that describes the symptoms of particular mental disorders. This classification system is found in the Diagnostic and Statistical Manual of Mental Disorders (DSM), published by the American Psychiatric Association. This manual contains almost 300 different mental disorders classified in sixteen categories:

  • Adjustment disorder — A person suffering from this disorder will exhibit an unusually intense or sustained emotional reaction to a change that has occurred in his or her life recently.

  • Anxiety disorders — The disorders within this category all share a symptom of an extreme fear or anxiety. They include phobias, panic attacks with or without agoraphobia, obsessive-compulsive disorder, and posttraumatic stress disorder.

  • Delirium, dementia, amnesia, and other cognitive disorders — The disorders within this group are a result of brain damage, including damage caused by degenerative diseases, head injury, stroke, or drug use.

  • Disorders usually first diagnosed in infancy, childhood, or adolescence — These disorders appear before adulthood and include mental retardation, developmental problems, and attention deficit disorders.

  • Dissociative disorders — These disorders are characterized by the separation of a person's experience from his conscious memory and include dissociative amnesia and dissociative identity disorder.

  • Eating disorders — These disorders are characterized by excessive overeating, undereating, or purging as a result of a fear of gaining weight. They include anorexia nervosa and bulimia nervosa.

  • Factitious disorders — These disorders are characterized by a person's attempt to fake physical or psychological illnesses.

  • Impulse control disorders — These disorders are marked by an inability to resist an impulse to participate in a behavior that is harmful to oneself or others. These include kleptomania, pyromania, pathological gambling, and intermittent explosive disorder.

  • Mental disorders due to a medical condition — These disorders are a result of a medical cause, such as a psychotic disorder resulting from epilepsy or a change in personality as a result of a brain injury.

  • Mood disorders — These disorders are characterized by extreme changes in mood, such as major depression, cyclothymia, dysthymia, and bipolar disorder.

  • Personality disorders — These disorders are a result of maladaptive patterns that disrupt a person's ability to function in everyday life and/ or cause extreme distress. They include narcissistic personality disorder, antisocial personality disorder, borderline personality disorder, obsessive-compulsive personality disorder, and paranoid personality disorder.

  • Psychotic disorders — These disorders are marked by delusions, hallucinations, or extreme disturbances in thinking (often the sufferer is considered to have lost touch with reality). They include schizophrenia and delusional disorder.

  • Sexual and gender-identity disorders — These disorders are marked by abnormal behavior regarding sexual functioning. They include sadomasochism, exhibitionism, psychosexual dysfunction, fetishism, and transsexualism.

  • Sleep disorders — These disorders are marked by a disruption in a person's normal sleeping patterns. They include insomnia, narcolepsy, and sleep apnea.

  • Somatoform disorders — These disorders are characterized by a complaint of a physical symptom for which no cause can be found. These include hypochondria and conversion disorder.

  • Substance-related disorders — These disorders are a result of the use of or withdrawal from a drug such as alcohol, caffeine, amphetamines, opiates, or nicotine.

  • The DSM gives a lot of detailed information concerning each mental disorder to help mental health professionals effectively and accurately diagnose a mental disorder, including symptoms, approximate age of onset (if applicable), prevalence of the disorder, and other pertinent information. The following sections will take a closer look at some of the most commonly known mental disorders.

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