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Summary: Defining Abnormal Behavior

Abnormal behavior can be defined in several different ways. More than ever, abnormal behavior syndromes such as schizophrenia, depression, and autism are understood as genetic disorders or brain diseases.

Society intervenes when an abnormal behavior becomes a harmful dysfunction. That label is used for behaviors that cause great distress to a person or threaten harm to others.

A social movement called deinstitution­alization spread throughout the United States and Canada in the 1960s and 1970s. It reflected changing attitudes in the early 60s, typified by the work of Thomas Szasz.

Szasz was a libertarian psychiatrist who declared mental illness was a "myth" because minds could not get sick. Rather, behaviors that threatened harm or were disapproved by society were labeled as "mental illness," in the view of Szasz.

Szasz argued that, rather than labeling people as ill and taking away their rights, society should give mentally disordered people the same rights and responsibilities as everybody else. This included the risk of imprisonment if they broke laws.

Within a few decades, people in most developed countries were no longer being held in institutions against their will. Exceptions were made when people presented a "clear and present danger" to themselves or others. Even then, the time of commitment was kept short if possible, and people were released when their symptoms cleared up.

One problem with deinstitutionalization was that few community support services existed to care for people who were released from mental institutions and lacked coping skills. Many of them ended up living on the streets or committed minor violations and were arrested.

Homeless people became increasingly common in large North American cities during the 1970s and 1980s. Up to 60% of so-called "homeless" people had identifiable disorders such as alcoholism.

In 1990 there were 3,600 "seriously mental ill" inmates in the Los Angeles County jail alone, making it the largest "de facto mental hospital" in the United States. In the United States as a whole, experts estimated that by 2012 there were 350,000 people with mental disorders in jail or prison, while only 35,000 were in mental hospitals.

Mental health clinicians use a reference manual called DSM, the Diagnostic and Statistical Manual of the American Psychiatric Association, This volume, currently in its fifth edition, provides a diagnostic shorthand for clinicians of all different types.

Therapists, doctors, and insurance companies use it as a standardized reference when specifying types of mental or behavioral dysfunction. The latest version, DSM-5, came out in 2013 and is a "living" document with ongoing changes to the official, online version.

The international version of DSM is called ICD (the International Catalog of Diseases). Unlike DSM, the ICD is only a coding system; it does not provide treatment guidelines. The two are compatible; American physicians have been using ICD codes since 1979, and ICD codes are provided with every DSM category.

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