AP Psychology Unit 5 Notes: Understanding Psychological Disorders

Introduction to Psychological Disorders

A psychological disorder (also called a mental disorder) is a pattern of thoughts, feelings, and/or behaviors that is distressing, dysfunctional, and/or dangerous (to oneself or others). In AP Psychology, the key idea is not just memorizing labels, but understanding how psychologists decide when a problem becomes a “disorder,” why classification matters, and how different perspectives explain the same symptoms.

What makes something a “disorder”?

Psychologists often describe disordered behavior using the “4 D’s” as a practical way to think:

• Deviance: The behavior is atypical for the person’s culture or context.
• Distress: The person experiences significant suffering.
• Dysfunction: The behavior interferes with daily life (school, work, relationships, self-care).
• Danger: The behavior creates risk of harm.

These are guidelines, not a checklist. For example, “deviance” can be tricky because unusual behavior is not automatically unhealthy (for example, nonconformist beliefs are not necessarily disordered). AP questions often test whether you can distinguish unusual from harmful/impairing.

Why classification matters: DSM and diagnostic thinking

Modern diagnosis commonly uses the DSM (Diagnostic and Statistical Manual of Mental Disorders), a handbook that provides standardized criteria for many disorders. The DSM aims to improve reliability—different clinicians should reach similar diagnoses when given the same information.

It’s important to understand the tradeoff:

• A clear diagnostic label can help with communication, treatment planning, and access to services (insurance, accommodations).
• But labels can also lead to stigma and can encourage people to think the disorder is the person’s entire identity (“she is bipolar” instead of “she has bipolar disorder”).

A classic idea related to labeling is that expectations can shape perception. When a label is attached, others may interpret ambiguous behavior as “symptoms,” and the person may begin to view themselves through the label.

The biopsychosocial approach: how AP Psych wants you to reason

AP Psychology emphasizes that disorders rarely have a single cause. The biopsychosocial approach explains behavior using interacting influences:

• Biological: genes, brain structure/function, neurotransmitters, hormones
• Psychological: learning history, cognition, coping skills, personality traits
• Social: relationships, culture, poverty, discrimination, trauma exposure

This matters because many exam questions describe a scenario and ask which factor (bio, psych, or social) best explains it—or how multiple factors combine.

Risk and resilience: diathesis-stress logic

A common framework is the diathesis-stress model, which says a disorder can result from a combination of:

• Diathesis: an underlying vulnerability (often genetic or biological, but can include temperament)
• Stress: environmental triggers (trauma, chronic conflict, major life changes)

You can think of it like this: vulnerability loads the “gun,” stress pulls the “trigger.” A misconception to avoid is assuming “genes equal destiny.” In this model, vulnerability increases risk but does not guarantee a disorder.

Culture and context

Culture shapes what symptoms look like, what people consider acceptable, and whether they seek help. A behavior that seems “deviant” in one culture might be normal in another. AP questions sometimes test whether you recognize culture as part of diagnosis and treatment (for example, how stigma or norms about emotional expression influence reporting symptoms).

Exam Focus

• Typical question patterns:
  • A vignette describes someone’s behavior; you identify which “D” (distress, dysfunction, danger, deviance) is most clearly present.
  • Compare medical model (disorders as illnesses to diagnose/treat) with biopsychosocial explanations.
  • Explain how labeling or stigma could affect a person’s experience.
• Common mistakes:
  • Treating “deviant” as automatically disordered without evidence of distress or impairment.
  • Assuming diagnoses are purely objective “blood tests” rather than criteria-based judgments.
  • Ignoring cultural context when judging whether behavior is abnormal.

Anxiety, Obsessive-Compulsive, and Trauma-Related Disorders

Anxiety is a normal emotion that helps you anticipate danger. It becomes disordered when it is excessive, persistent, and impairs functioning. AP Psychology often tests whether you can distinguish ordinary fear from clinically significant anxiety, and whether you can connect symptoms to learning and biology.

Anxiety disorders: fear and worry that hijack functioning

Anxiety disorders involve intense fear or worry that is out of proportion to the situation.

Generalized Anxiety Disorder (GAD)

Generalized anxiety disorder (GAD) is characterized by persistent, excessive worry across many areas of life (school, health, family), often with physical symptoms like muscle tension or sleep problems.

How it works: GAD is less about one specific trigger and more about a mind stuck in “what if?” mode. Cognitively, people may overestimate threat and underestimate coping ability.

Example in action: A student worries daily about grades, friendships, health, and finances even when things are going well, and can’t “turn off” the worry at night.

Common misconception: GAD is not simply “being a worrier.” The key is impairment and persistence.

Panic Disorder

Panic disorder involves recurrent panic attacks—sudden surges of intense fear with strong physical sensations (racing heart, shortness of breath, dizziness)—and persistent worry about having future attacks.

How it works: A panic attack can condition fear of the bodily sensations themselves. If your brain learns “racing heart equals danger,” you may become hypervigilant to normal arousal, which can trigger more panic.

Example in action: After one terrifying panic attack in a grocery store, a person starts avoiding stores and constantly monitors their breathing.

Phobias

A phobia is an intense, irrational fear of a specific object or situation (for example, heights, spiders). The fear leads to avoidance.

How it works (learning emphasis):

• Classical conditioning can link a neutral stimulus (a dog) with fear after a bad bite.
• Operant conditioning maintains it: avoidance reduces anxiety in the short term (negative reinforcement), which strengthens avoidance.
• Observational learning can also create phobias by watching others react fearfully.

Example in action: Someone avoids elevators after getting stuck once, and the avoidance spreads to other enclosed spaces.

Obsessive-Compulsive and related disorders

In AP Psychology, it’s crucial to separate OCD from everyday neatness and from the personality disorder with a similar name (discussed later).

Obsessive-compulsive disorder (OCD) involves:

• Obsessions: unwanted, intrusive thoughts or urges that cause distress
• Compulsions: repetitive behaviors or mental acts performed to reduce distress or prevent a feared event

Why it matters: OCD shows how anxiety can be driven internally. The compulsion is not done for pleasure; it’s done to relieve unbearable doubt or fear.

How it works: Compulsions are strongly reinforced because they reduce anxiety immediately. That short-term relief teaches the brain “this ritual works,” even if the ritual is irrational.

Example in action: A person has intrusive fears about contamination. They wash their hands repeatedly until it “feels right,” even though they know it’s excessive.

Common misconception: Liking organization is not OCD. OCD requires intrusive distressing obsessions and compulsions that interfere with life.

Trauma- and stressor-related disorders

These disorders are tied directly to exposure to a stressor.

Post-Traumatic Stress Disorder (PTSD)

Post-traumatic stress disorder (PTSD) can occur after exposure to a traumatic event and includes symptoms such as:

• Intrusion (flashbacks, nightmares)
• Avoidance (of reminders)
• Negative changes in mood/cognition (guilt, numbness)
• Hyperarousal (startle response, sleep problems)

How it works: Trauma can condition fear responses to cues that resemble the event. Biologically, heightened arousal systems can keep the body in “threat mode.” Cognitively, the person may develop beliefs like “the world is completely unsafe,” which sustains vigilance and avoidance.

Example in action: After a serious car crash, a person has nightmares, avoids driving, and feels constantly on edge when hearing screeching brakes.

Acute Stress Disorder

Acute stress disorder is similar to PTSD but occurs in the shorter time window soon after trauma. In AP-style thinking, it helps you understand that trauma reactions can be immediate, and that duration matters in diagnosis.

Exam Focus

• Typical question patterns:
  • Identify GAD vs panic disorder vs specific phobia from a vignette.
  • Explain OCD using negative reinforcement (ritual reduces anxiety, making the ritual more likely).
  • Apply conditioning concepts to phobias or PTSD (triggers, avoidance behavior).
• Common mistakes:
  • Calling any strong fear a “phobia” without evidence of avoidance and impairment.
  • Confusing panic attacks (brief, intense episodes) with generalized anxiety (chronic worry).
  • Describing OCD as “liking things clean” rather than obsessions plus compulsions.

Depressive and Bipolar Disorders

Mood disorders are not just “feeling sad” or “being moody.” They involve sustained disruptions in mood that affect thinking, motivation, sleep, and behavior. Understanding these disorders matters because they are common, impairing, and frequently assessed through symptom-based vignettes on AP exams.

Depressive disorders: persistent low mood and loss of pleasure

Major depressive disorder (MDD) involves at least one major depressive episode with symptoms such as:

• depressed mood and/or anhedonia (loss of interest/pleasure)
• changes in sleep and appetite
• fatigue, slowed movement or agitation
• feelings of worthlessness or excessive guilt
• difficulty concentrating
• thoughts of death or suicide

How it works (multiple levels):

• Biological: mood regulation involves brain circuits and neurotransmitter systems. (AP courses often discuss serotonin/norepinephrine in a broad way, but the key is that biology influences mood regulation rather than providing a simple “chemical imbalance” story.)
• Cognitive: depressed thinking often includes negative beliefs about the self, world, and future (sometimes taught as a “cognitive triad”), and a tendency to interpret events pessimistically.
• Behavioral: reduced activity can shrink opportunities for pleasure or success, which can deepen low mood.

Example in action: After weeks of feeling numb and hopeless, a student stops seeing friends, can’t sleep, struggles to focus, and feels “like a burden.”

Common misconception: Depression is not just sadness. Many people with depression report emotional numbness, irritability, or loss of pleasure rather than constant crying.

Persistent Depressive Disorder

Persistent depressive disorder (often called dysthymia) involves a longer-lasting pattern of depressed mood. It’s often less intense than MDD day-to-day, but its long duration can be highly impairing.

Bipolar disorders: depression plus episodes of elevated mood

Bipolar disorders involve shifts between depressive states and manic or hypomanic states.

Mania and hypomania

A manic episode is a distinct period of abnormally elevated or irritable mood and increased energy, often including:

• decreased need for sleep
• inflated self-esteem or grandiosity
• pressured speech, racing thoughts
• impulsive or risky behavior

Hypomania is similar but less severe and typically causes less impairment than full mania.

Why this distinction matters: It is common for people to seek help during depression but not recognize hypomania/mania as part of the problem. On exams, bipolar is often tested by giving a depression history plus a period of unusually high energy and risky behavior.

Bipolar I and Bipolar II (conceptual distinction)

• Bipolar I disorder involves at least one manic episode (depression may also occur).
• Bipolar II disorder involves hypomanic episodes and major depressive episodes (no full manic episodes).

Example in action: Someone has months of severe depression, then a week of sleeping only a few hours, talking rapidly, starting unrealistic projects, and spending money impulsively.

Common misconception: Bipolar disorder is not just “mood swings within a day.” The episodes last long enough to represent a meaningful change from typical functioning.

Suicide risk and responsible thinking

AP Psychology sometimes includes questions about warning signs and risk factors. The key academic point is that suicidal thinking is associated with factors like severe depression, hopelessness, prior attempts, substance use, and lack of support. In a classroom context, you should treat this as a mental health safety topic: real people should seek immediate professional help.

Exam Focus

• Typical question patterns:
  • Distinguish MDD from persistent depressive disorder based on intensity vs duration.
  • Identify bipolar disorder from a vignette that includes mania/hypomania symptoms.
  • Apply cognitive explanations (negative beliefs, pessimistic interpretation) to depressive symptoms.
• Common mistakes:
  • Confusing bipolar disorder with everyday emotional variability or stress reactions.
  • Assuming depression always looks like sadness (ignoring anhedonia, sleep/appetite changes, concentration issues).
  • Missing mania clues because they’re described as “productive” or “energized” without noting impairment/risk.

Schizophrenia and Dissociative Disorders

These disorders are frequently misunderstood. AP Psychology emphasizes careful symptom identification and distinguishing between psychosis (loss of contact with reality) and dissociation (disruptions in identity/memory/awareness).

Schizophrenia: a disorder involving psychosis

Schizophrenia is a severe disorder characterized by psychosis, including disturbances in perception, thought, and behavior.

Positive vs negative symptoms

AP Psychology commonly organizes schizophrenia symptoms into:

• Positive symptoms: additions to normal experience
  • Hallucinations: sensory experiences without external stimuli (often auditory)
  • Delusions: firmly held false beliefs (for example, paranoia)
  • disorganized speech or behavior
• Negative symptoms: reductions in normal functioning
  • reduced emotional expression (flat affect)
  • avolition (reduced motivation)
  • reduced speech or social withdrawal

Why this matters: Many students think schizophrenia equals “multiple personalities.” That is incorrect. Schizophrenia is primarily about psychosis and disorganization, not separate identities.

How schizophrenia develops: integrated explanations

AP Psychology often highlights that schizophrenia reflects a combination of:

• Biology: genetic risk is significant; brain differences and neurotransmitter systems (especially dopamine pathways) are often discussed as contributing to psychotic symptoms.
• Brain development and environment: the disorder is often framed using diathesis-stress logic—vulnerability plus stress.
• Cognitive factors: difficulties filtering and organizing information can contribute to disorganized thought.

Students sometimes over-simplify to “too much dopamine.” A better AP-level answer is that neurotransmitter dysregulation is one important part of a broader brain-based vulnerability interacting with stress.

Course-relevant timeline ideas

Schizophrenia typically emerges in late adolescence to early adulthood. Early signs (sometimes described as a prodromal phase) may include social withdrawal or odd thinking before clear psychotic symptoms appear.

Example in action: A young adult begins believing that strangers are sending secret messages through TV, hears voices commenting on their actions, and becomes disorganized in speech and daily routines.

Dissociative disorders: disruptions in consciousness or identity

Dissociation refers to a disruption in the normal integration of memory, consciousness, identity, or perception. Dissociative experiences can occur mildly in everyday life (daydreaming, “highway hypnosis”), but dissociative disorders are more severe and impairing.

Dissociative Amnesia

Dissociative amnesia involves difficulty recalling important personal information, usually after stress or trauma, that can’t be explained by ordinary forgetting.

Example in action: After a traumatic event, someone cannot recall key details about their past life even though their general memory ability is intact.

Dissociative Identity Disorder (DID)

Dissociative identity disorder (DID) involves the presence of two or more distinct identity states along with memory gaps beyond ordinary forgetting.

Why it matters: DID is controversial and often sensationalized in media. For AP Psychology, the main goal is careful definition and differentiation from schizophrenia. DID is not primarily delusions/hallucinations; it is a disorder of identity and memory.

Common misconception: DID is not the same as “split personality” in the casual sense, and it is not synonymous with violent behavior.

Depersonalization/Derealization Disorder

This disorder involves persistent experiences of:

• Depersonalization: feeling detached from yourself (as if observing yourself)
• Derealization: feeling that the world is unreal or dreamlike

Example in action: A person feels like they are watching their life from outside their body and that their surroundings look “fake,” which causes distress.

Exam Focus

• Typical question patterns:
  • Identify schizophrenia based on hallucinations/delusions and distinguish positive vs negative symptoms.
  • Explain schizophrenia using a biopsychosocial or diathesis-stress perspective.
  • Distinguish schizophrenia from DID in a vignette (psychosis vs identity disruption).
• Common mistakes:
  • Claiming schizophrenia is “multiple personalities.”
  • Treating hallucinations as automatically schizophrenia (they can occur in other conditions, substances, or medical issues).
  • Confusing dissociation with deliberate lying or attention-seeking rather than a real disruption in memory/identity.

Personality and Neurodevelopmental Disorders

This section ties together long-term patterns (personality) with early-emerging developmental differences (neurodevelopmental). AP Psychology often uses these topics to test whether you can identify stable traits across time versus episodic symptoms.

Personality disorders: enduring, inflexible patterns

A personality disorder is an enduring pattern of inner experience and behavior that deviates from cultural expectations, is inflexible, begins by adolescence/early adulthood, is stable over time, and leads to distress or impairment.

Why this matters: Personality disorders are not just “bad personalities.” They involve rigid patterns that make relationships and work persistently difficult. They also highlight a key AP theme: the boundary between normal traits and disordered extremes.

Clusters (a common organizing tool)

Personality disorders are often grouped into clusters:

• Cluster A (odd/eccentric): suspiciousness, detachment
• Cluster B (dramatic/emotional/erratic): impulsivity, instability
• Cluster C (anxious/fearful): high anxiety, need for control

This clustering is a study tool, not a perfect system—people don’t always fit neatly.

Antisocial Personality Disorder (ASPD)

Antisocial personality disorder (ASPD) involves a pattern of disregarding and violating the rights of others, often including deceitfulness, impulsivity, irritability, irresponsibility, and lack of remorse.

How it works (AP-level explanation): Research often emphasizes both biological factors (such as low arousal to threat in some individuals) and environmental factors (such as harsh or inconsistent parenting). AP courses also commonly connect ASPD to the concept of psychopathy (callousness, shallow affect), while noting these are related but not identical terms.

Example in action: A person repeatedly exploits others, lies, and breaks rules without guilt, leading to chronic legal and relationship problems.

Misconception to avoid: ASPD is not the same as being “mean sometimes.” It’s a pervasive pattern across situations.

Borderline Personality Disorder (BPD)

Borderline personality disorder (BPD) involves instability in relationships, self-image, and emotions, along with impulsivity. Fear of abandonment and intense, rapidly shifting emotions are common.

Example in action: Someone alternates between idealizing and devaluing friends, feels chronically empty, and engages in impulsive actions during emotional distress.

A common AP pitfall is confusing BPD with bipolar disorder. Bipolar involves episodes of mania/hypomania and depression; BPD is more about chronic instability, especially in relationships and self-concept.

Narcissistic Personality Disorder

Narcissistic personality disorder involves grandiosity, need for admiration, and lack of empathy.

Example in action: A person dominates conversations, reacts with rage to criticism, and exploits others to maintain a superior self-image.

Obsessive-Compulsive Personality Disorder (OCPD)

Obsessive-compulsive personality disorder (OCPD) involves a preoccupation with orderliness, perfectionism, and control.

Critical distinction: OCPD is not OCD. OCD has intrusive obsessions and compulsions performed to reduce anxiety. OCPD is a personality style—rigid perfectionism and control—that the person may see as “correct,” not as an unwanted intrusion.

Neurodevelopmental disorders: early-emerging differences in brain development

Neurodevelopmental disorders begin in childhood and reflect differences in brain development that affect learning, attention, behavior, and social functioning.

Attention-Deficit/Hyperactivity Disorder (ADHD)

ADHD is characterized by patterns of inattention and/or hyperactivity-impulsivity that interfere with functioning.

How it works: AP Psychology often frames ADHD in terms of differences in executive functions—skills like sustained attention, inhibition, planning, and working memory. Environmental structure (consistent routines, clear expectations) can strongly influence how impairing symptoms become.

Example in action: A student frequently loses materials, forgets instructions, interrupts, and struggles to stay seated or focused even when trying.

Misconception to avoid: ADHD is not simply “too much energy” or “bad parenting.” It is a neurodevelopmental pattern with biological and environmental components.

Autism Spectrum Disorder (ASD)

Autism spectrum disorder (ASD) involves differences in social communication and restricted/repetitive patterns of behavior or interests. The term “spectrum” matters: people vary widely in strengths, support needs, language abilities, and sensory sensitivities.

How it works: ASD reflects differences in social processing and sensory/behavioral regulation. AP questions may describe difficulty reading social cues, strong preference for routines, intense interests, or sensory sensitivities.

Example in action: A child has difficulty with back-and-forth conversation, becomes distressed when routines change, and engages in repetitive movements that help regulate emotion.

Tourette’s Disorder (often included in AP overviews)

Tourette’s disorder involves multiple motor tics and at least one vocal tic lasting for an extended period.

Example in action: A person has repeated blinking and throat-clearing tics that increase under stress.

Important misconception: Tourette’s is not defined by swearing; that symptom is rare and not required.

Exam Focus

• Typical question patterns:
  • Identify personality disorders via long-term patterns (not temporary episodes) and apply cluster descriptions.
  • Distinguish ADHD (attention/inhibition difficulties) from typical childhood energy or situational boredom.
  • Differentiate OCD from OCPD in a vignette (intrusive obsessions/compulsions vs rigid perfectionism/control).
• Common mistakes:
  • Confusing BPD with bipolar disorder without checking for manic/hypomanic episodes.
  • Treating ASD as a single “look” or assuming all autistic people have the same abilities or challenges.
  • Assuming personality disorders are just moral failings rather than enduring, impairing patterns influenced by multiple factors.