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Psychological
Disorders

Understanding how we explain, classify, and diagnose psychological disorders using modern frameworks and the DSM-5.

AP Psychology

What Is a Psychological Disorder?

A psychological disorder is a syndrome marked by a clinically significant disturbance in an individual's cognition, emotion regulation, or behavior. It reflects a dysfunction in biological, psychological, or developmental processes underlying mental functioning.

The Four D's of Abnormality

Deviance
Behavior that differs from cultural or statistical norms
Distress
The individual experiences significant personal suffering
Dysfunction
Impairment in daily life: work, relationships, self-care
Danger
Risk of harm to oneself or others (least common criterion)

Historical Perspectives on Disorders

1
Supernatural Model: Ancient cultures attributed abnormal behavior to demonic possession, evil spirits, or divine punishment.
2
Medical Model: Philippe Pinel and others reframed disorders as illnesses with biological causes that can be diagnosed and treated.
3
Biopsychosocial Model: Modern psychology integrates biological, psychological, and social-cultural factors.

The Biopsychosocial Framework

Psychological Disorder Biological Genes, brain chemistry Psychological Cognition, learning, stress Social-Cultural Culture, poverty, family dynamics

The DSM-5: The Classification System

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) is published by the American Psychiatric Association. It provides standardized criteria clinicians use to diagnose psychological disorders.

Descriptive
Lists observable symptoms rather than assumed causes
Categorical
Groups disorders into distinct diagnostic categories
Standardized
Ensures consistent diagnosis across clinicians and cultures

Major DSM-5 Categories

DSM-5 Anxiety Disorders Depressive Disorders Bipolar Disorders Schizophrenia Spectrum Personality Disorders Trauma & Stressor Related

DSM-5 vs. ICD-11

DSM-5 ICD-11
Published by American Psychiatric Association World Health Organization
Primary Use Diagnosis & clinical research Global health statistics & billing
Geographic Focus United States (primarily) International (193 countries)
Approach Detailed diagnostic criteria Broader clinical descriptions
AP Exam Focus ★ High importance Mentioned for context

How Clinicians Diagnose Disorders

1
Gather information: Clinical interviews, behavioral observations, psychological testing, and medical history.
2
Apply the Four D's: Assess whether the behavior is deviant, causes distress, produces dysfunction, or involves danger.
3
Match DSM-5 criteria: Compare symptoms against specific diagnostic criteria for candidate disorders.
4
Rule out alternatives: Eliminate medical conditions, substance effects, and other disorders that better explain symptoms.
5
Consider context: Cultural norms, life circumstances, and developmental stage all influence whether behavior is truly disordered.

Example: Generalized Anxiety Disorder

Case: Maria, 28, reports constant worry about her job, finances, and health for over 8 months. She has trouble sleeping, feels restless, and has difficulty concentrating. Her worry is disproportionate to the actual circumstances.

Deviance ✓
Worry far exceeds what is typical for her situations
Distress ✓
Sleep loss, restlessness, and personal suffering
Dysfunction ✓
Impaired concentration affecting work performance

Example: Major Depressive Disorder

Case: James, 35, has experienced persistent sadness, loss of interest in activities he once enjoyed, significant weight loss, insomnia, and feelings of worthlessness for three weeks. He has difficulty getting out of bed and has withdrawn from friends.

1
Core symptoms present: Depressed mood and loss of interest (anhedonia): both are present.
2
Additional symptoms: Weight change, insomnia, feelings of worthlessness: that is 3 more, totaling 5 of 9 criteria (minimum required).
3
Duration met: Symptoms lasting at least 2 weeks: James has had them for 3 weeks.
4
Impairment confirmed: Social withdrawal and inability to function at work satisfy the dysfunction criterion.

Distinguishing Similar Disorders

Case: A patient shows extreme sadness, loss of energy, and hopelessness. Could this be Major Depressive Disorder or Bipolar Disorder?

MDD Bipolar Disorder
Depressive Episodes ✓ Present ✓ Present
Manic Episodes ✕ Absent ✓ Present
Key Differentiator Unipolar depression only Cycling between highs and lows
Treatment Antidepressants, CBT Mood stabilizers (e.g., lithium)

Explaining Disorders: Perspectives

Biological
Genetics, neurotransmitter imbalances, brain structure abnormalities
Cognitive
Maladaptive thought patterns, irrational beliefs, learned helplessness
Behavioral
Disorders are learned through conditioning, reinforcement, and modeling
Psychodynamic
Unconscious conflicts, childhood experiences, defense mechanisms
Sociocultural
Cultural norms, poverty, discrimination, and social support

The Diathesis-Stress Model

Diathesis (Vulnerability) + Stress (Environmental Trigger) Disorder Manifests Examples: Genetic predisposition Brain chemistry Temperament Examples: Trauma or abuse Job loss Social isolation

Labeling and Its Consequences

While classification systems like the DSM-5 enable effective treatment, diagnostic labels can also carry significant consequences. David Rosenhan's famous 1973 study demonstrated how labels can bias perception.

Benefits of Labels
Enable communication, guide treatment, support research, facilitate access to services
Risks of Labels
Stigma, self-fulfilling prophecy, confirmation bias, loss of individual identity

Common Mistakes on the AP Exam

✕ Confusing "Abnormal" with "Disordered"
Not all unusual behavior is a disorder. Cultural deviance alone does not equal a psychological disorder: distress and dysfunction must also be present.
✕ Mixing Up MDD and Bipolar
Both include depressive episodes, but bipolar disorder requires at least one manic or hypomanic episode. Always look for the "high" phase.
✕ Single-Cause Explanations
Attributing a disorder to only one factor (e.g., "depression is just a chemical imbalance") ignores the biopsychosocial model the AP exam emphasizes.

Question 1 of 5

Which of the following best describes the biopsychosocial model of psychological disorders?

Question 2 of 5

A clinician is evaluating whether a patient's behavior constitutes a psychological disorder. According to the "Four D's" framework, which combination of criteria should the clinician consider?

Question 3 of 5

The diathesis-stress model suggests that psychological disorders develop when:

Question 4 of 5

Both researchers would most likely agree that:

Question 5 of 5

Rosenhan's 1973 "pseudopatient" study primarily demonstrated which limitation of psychiatric diagnosis?