Defining Psychological Disorders (College Board AP® Psychology): Study Guide

Defining disordered behavior

• A psychological disorder (or mental disorder/psychopathology) is a pattern of behavior or mental processes that causes significant disturbance to the individual or others

• Defining what counts as a disorder is complex

  • There is no clear boundary between normal and abnormal behavior

• The field of abnormal psychology (or psychopathology) studies psychological disorders

  • They range from common conditions (e.g. anxiety, depression) to rarer and more severe disorders (e.g.schizophrenia)

• Psychologists typically use three key criteria to identify disorder:

  • dysfunction

  • distress

  • deviance

Dysfunction

• Dysfunction is behavior or mental processes that significantly impair a person's ability to function in their daily life

  • E.g. work, education, relationships, or self-care

• To be considered disordered, the impairment must be meaningful and persistent, not temporary

  • E.g. a fear of open spaces (agoraphobia) that prevents a person from leaving their home, affecting their employment and relationships

Distress

• Distress is the subjective experience of suffering caused by a mental state or behavior

• It reflects how the individual feels, rather than how others judge the behavior

  • E.g. a person with depression who experiences persistent sadness, hopelessness, and emotional pain is experiencing distress

• However, distress is not always present (e.g. some personality disorders), so it cannot be used alone to define a disorder

Deviance

• Deviance refers to behavior that is statistically rare or violates social norms of a given society or culture

• What counts as deviant varies across cultures and over time.

  • E.g. having visual hallucinations may be considered a symptom of disorder in some cultures but not in others

• Deviance alone is insufficient to define disorder

  • Many uncommon behaviors (e.g. exceptional ability) are deviant in a statistical sense but are not disorders

The role of cultural context

• All three criteria above are shaped by cultural norms:

  • expectations influence what counts as dysfunction

  • cultural values shape what is experienced as distressing

  • social norms determine what is considered deviant

    • E.g. homosexuality was classified as a disorder in the DSM until 1973, reflecting societal attitudes rather than a change in behavior

• Cultural biases can affect diagnosis in the following ways:

  • behaviors of minority groups may be misinterpreted

  • some groups may be over- or under-diagnosed

  • norms from one culture may be wrongly applied to another

Consequences of diagnosis

• Diagnosing a psychological disorder has both benefits and limitations:

The DSM & ICD

• Diagnosing a psychological disorder requires:

  • specialized clinical training to recognize patterns of disordered behavior

  • standardized, evidence-based tools

  • consideration of cultural context, individual history, and the 3D criteria

• Diagnosis should only be made by trained professionals, not by lay people

The Diagnostic & Statistical Manual (DSM)

• The DSM is published by the American Psychiatric Association (APA) and is the primary diagnostic system used in the United States

• It provides:

  • a classification system of mental disorders

  • diagnostic criteria (symptoms, duration, level of impairment)

  • guidance on differential diagnosis (distinguishing similar disorders)

• The current version is the DSM-5-TR

• The DSM is periodically updated to reflect new research and changes in clinical practice

  • E.g. later editions of the DSM introduced more evidence-based, symptom-focused criteria and reorganized disorder categories

The International Classification of Mental Disorders (ICD)

• The ICD is developed by the World Health Organization (WHO) and is used internationally, particularly in Europe and developing countries

• It:

  • classifies both mental and physical disorders

  • provides diagnostic criteria for mental disorders

  • supports global health monitoring and epidemiology

• The current version is ICD-11

• Like the DSM, it is regularly revised to reflect advances in research and practice

DSM vs ICD

• Both systems evolve over time as:

  • scientific understanding of psychological disorders improves

  • cultural and societal norms shift, which influence diagnosis change

  • diagnostic categories are refined

• However, they remain subject to debate, particularly regarding:

  • boundaries between disorders

  • thresholds for diagnosis

  • cultural bias in diagnostic criteria