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Psychological
Disorders

Learn to identify and distinguish the major categories of psychological disorders using the DSM-5 classification system and key diagnostic criteria.

AP Psychology

What Is a Psychological Disorder?

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

The DSM-5 Classification System

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) is the standard reference used by clinicians in the United States to diagnose psychological disorders. It organizes disorders into categories based on shared features.

Descriptive
Classifies by observable symptoms, not assumed causes
Categorical
Groups disorders with similar features into distinct categories
Dimensional
Acknowledges severity can vary on a continuum within categories

Why Categories Matter

Categorization allows clinicians to communicate efficiently, select evidence-based treatments, and conduct research across populations. For the AP exam, you must be able to match symptoms to the correct disorder category.

1
Diagnosis: Identifying the correct category guides treatment selection.
2
Communication: Shared labels let professionals discuss cases precisely.
3
Research: Categories enable large-scale epidemiological studies.
4
AP Exam: Questions test your ability to classify symptoms into DSM-5 categories.

Major Disorder Categories

DSM-5 Categories Anxiety Disorders Depressive Disorders Bipolar Disorders Schizophrenia Personality Disorders OCD & Related Dissociative Disorders Somatic Symptom Trauma & Stressor These are the categories most frequently tested on the AP exam.

Anxiety Disorders

Anxiety disorders share features of excessive fear (emotional response to perceived or real threat) and anxiety (anticipation of future threat). They differ from normal anxiety by being persistent and disproportionate.

GAD
Generalized Anxiety Disorder: excessive worry about many things for 6+ months
Panic Disorder
Recurrent unexpected panic attacks with intense physical symptoms
Specific Phobia
Marked fear of a specific object or situation (e.g., heights, spiders)

Depressive & Bipolar Disorders

Major Depressive Disorder
Depressed mood or loss of interest for 2+ weeks, with changes in sleep, appetite, energy, concentration, and self-worth
Bipolar I
At least one manic episode: abnormally elevated mood, energy, decreased need for sleep, risky behavior

Schizophrenia Spectrum

Schizophrenia and other psychotic disorders are defined by abnormalities in one or more of the following domains:

1
Delusions: Fixed false beliefs not amenable to change (e.g., persecution, grandeur).
2
Hallucinations: Perception-like experiences without external stimulus (most commonly auditory).
3
Disorganized thinking: Derailment, loose associations, incoherent speech.
4
Negative symptoms: Diminished emotional expression, avolition, social withdrawal.

OCD, Dissociative, & Trauma Disorders

OCD
Obsessions (intrusive thoughts) and compulsions (repetitive behaviors) that are time-consuming and distressing
Dissociative
Disruption of consciousness, memory, identity, or perception: includes DID and dissociative amnesia
PTSD
Following trauma exposure: intrusion symptoms, avoidance, negative cognitions, hyperarousal lasting 1+ month

Personality Disorders

Personality disorders are characterized by enduring patterns of inner experience and behavior that deviate markedly from cultural expectations, are pervasive and inflexible, and lead to distress or impairment.

Cluster A: Odd/Eccentric
Paranoid, Schizoid, Schizotypal: characterized by social withdrawal and unusual thinking
Cluster B: Dramatic/Erratic
Antisocial, Borderline, Histrionic, Narcissistic: emotional instability and impulsivity
Cluster C: Anxious/Fearful
Avoidant, Dependent, Obsessive-Compulsive: excessive anxiety and fear

Key Distinction: Anxiety vs. OCD vs. PTSD

Anxiety Disorders OCD PTSD
Core Feature Excessive fear/worry Obsessions + compulsions Trauma re-experiencing
Trigger Varies (general or specific) Intrusive thoughts Traumatic event
DSM-5 Category Anxiety Disorders OCD & Related Trauma & Stressor
Key Behavior Avoidance Ritualistic behavior Hypervigilance

How to Classify a Disorder

1
Identify the primary symptom: Is it fear, sadness, psychosis, trauma, obsessions, or personality pattern?
2
Check duration and severity: Does it meet the DSM-5 threshold (e.g., 2 weeks for depression, 6 months for GAD)?
3
Rule out similar categories: Is anxiety the core issue, or is it secondary to obsessions, trauma, or mood swings?
4
Check for functional impairment: Does the pattern cause clinically significant distress or impairment?
5
Match to the correct DSM-5 category: Select the category whose defining features best match the symptom profile.

Example 1: Identifying the Category

1
Primary symptom: Excessive, generalized worry across multiple domains.
2
Duration: 8 months (exceeds the 6-month threshold).
3
Rule-out: No obsessions/compulsions (not OCD), no trauma (not PTSD), no mood cycling (not bipolar).
4
Classification: Generalized Anxiety Disorder (Anxiety Disorders category).

Example 2: Psychotic Features

1
Delusions: Persecutory beliefs (government monitoring) are a positive symptom.
2
Hallucinations: Auditory hallucinations (voices commenting) are a positive symptom.
3
Negative symptoms: Social withdrawal and functional decline.
4
Classification: Schizophrenia Spectrum (symptoms lasting 6+ months with functional impairment).

Example 3: Mood vs. Personality

Not Bipolar
Bipolar mood episodes last days to weeks. This patient's shifts last hours and are triggered by relationships.
Correct: BPD
Borderline Personality Disorder: enduring pattern of instability in relationships, self-image, and affect, with marked impulsivity.

Common Mistakes

✕ OCD = Anxiety Disorder
In the DSM-5, OCD is in its own separate category: Obsessive-Compulsive and Related Disorders.
✕ Confusing Bipolar & BPD
Bipolar has distinct mood episodes lasting days. BPD has rapid, relationship-triggered mood shifts and is a personality disorder.
✕ PTSD = Anxiety
PTSD is classified under Trauma and Stressor-Related Disorders, not Anxiety Disorders, in DSM-5.
✕ DID = Schizophrenia
Dissociative Identity Disorder involves identity disruption, not psychosis. Schizophrenia involves hallucinations and delusions.
✕ Sadness = Depression
Normal sadness is adaptive. Major Depressive Disorder requires 2+ weeks of symptoms with functional impairment.

Summary of Categories

Category Core Feature Key Example
Anxiety Disorders Excessive fear/worry GAD, Panic, Phobias
Depressive Disorders Persistent sadness/loss of interest Major Depressive Disorder
Bipolar Disorders Mood cycling (mania + depression) Bipolar I, Bipolar II
Schizophrenia Spectrum Psychosis (delusions, hallucinations) Schizophrenia
OCD & Related Obsessions and compulsions OCD, Body Dysmorphic
Trauma & Stressor Response to traumatic event PTSD, Acute Stress
Dissociative Disorders Disruption in identity/memory DID, Dissociative Amnesia
Personality Disorders Enduring maladaptive patterns Antisocial, Borderline

Question 1 of 5

A patient experiences recurrent, intrusive thoughts about contamination and spends hours each day washing her hands. Under the DSM-5, this would best be classified as which category?

Question 2 of 5

Which of the following is a negative symptom of schizophrenia?

Question 3 of 5

A soldier returns from combat and experiences flashbacks, nightmares, and hypervigilance for three months. Which DSM-5 category best applies?

Question 4 of 5

A person has a lifelong pattern of disregard for others' rights, deceitfulness, impulsivity, and lack of remorse. This best fits which category?

Question 5 of 5

Which of the following best distinguishes Bipolar I from Borderline Personality Disorder?