Chapter 15: Psychological Disorders¶

Summary¶

This chapter provides in-depth coverage of the major disorder categories assessed on the AP exam. Building on Chapter 14's foundations, students examine neurodevelopmental disorders (ADHD, autism spectrum disorder), the schizophrenia spectrum (positive and negative symptoms in detail), anxiety disorders (agoraphobia, social anxiety disorder, generalized anxiety disorder), obsessive-compulsive disorder and hoarding disorder, personality disorder clusters with focus on antisocial and borderline personality disorders, and feeding and eating disorders. The diathesis-stress model and the cognitive perspective on disorders provide integrating frameworks. The chapter also introduces the major psychotherapy modalities — psychodynamic, behavioral, humanistic, cognitive therapy, systematic desensitization, group therapy, and hypnosis — and closes with the importance of cultural humility and the problem of ethnocentrism in diagnosis.

Concepts Covered¶

This chapter covers the following 23 concepts from the learning graph:

Agoraphobia
Obsessive-Compulsive Disorder
Feeding and Eating Disorders
Personality Disorder Clusters
Psychodynamic Therapy
Behavioral Therapy
Humanistic (Person-Centered) Therapy
Group Therapy
Hypnosis in Treatment
ADHD
Autism Spectrum Disorder
Cognitive Perspective on Disorders
Positive Symptoms of Schizophrenia
Negative Symptoms of Schizophrenia
Hoarding Disorder
Antisocial Personality Disorder
Borderline Personality Disorder
Systematic Desensitization
Social Anxiety Disorder
Cognitive Therapy
Diathesis-Stress Model
Generalized Anxiety Disorder
Ethnocentrism

Prerequisites¶

This chapter builds on concepts from:

Chapter 14: Health Psychology and Introduction to Psychological Disorders

15.1 Neurodevelopmental Disorders¶

Mascot-welcome

Psy the Owl welcoming you to Chapter 15 Welcome to Chapter 15 — the full clinical survey!

In Chapter 14, you built the conceptual framework: the biopsychosocial model, the DSM/ICD systems, the four explanatory perspectives, and the diathesis-stress model. Now we populate that framework with the disorders themselves — anxiety disorders, OCD, schizophrenia, personality disorders, neurodevelopmental disorders, and more.

This chapter also introduces the major therapy approaches that match many of these disorders. As you read, notice the logical connections: behavioral therapies treat disorders understood through a behavioral lens; cognitive therapy treats disorders understood through a cognitive lens. The theories generate the treatments.

Let's think about that! 🦉

Neurodevelopmental disorders are disorders that emerge during development, involving atypical brain development that affects behavior, social functioning, or cognition. They are typically diagnosed in childhood, though they often persist into adulthood.

ADHD¶

Attention-Deficit/Hyperactivity Disorder (ADHD) is characterized by persistent patterns of inattention and/or hyperactivity-impulsivity that interfere with functioning and development. There are three presentations:

Predominantly inattentive: Difficulty sustaining attention, easily distracted, forgetful, loses materials
Predominantly hyperactive-impulsive: Fidgeting, difficulty staying seated, interrupting, acting before thinking
Combined: Both patterns

ADHD affects approximately 5–10% of school-aged children and persists into adulthood in a majority of cases. The biological basis involves underactivity in prefrontal cortex circuits responsible for executive function and inhibitory control, and dysregulation of dopaminergic and noradrenergic systems. Stimulant medications (methylphenidate, amphetamine) increase dopamine and norepinephrine, improving attention and reducing hyperactivity for many individuals.

Autism Spectrum Disorder¶

Autism Spectrum Disorder (ASD) is characterized by persistent deficits in social communication and interaction, and restricted, repetitive patterns of behavior, interests, or activities. ASD is a spectrum — encompassing individuals with very different levels of support need, from highly verbal individuals who struggle primarily with social pragmatics to those requiring substantial daily support.

Key features: - Difficulty with social-emotional reciprocity (back-and-forth conversation, sharing emotions) - Reduced eye contact, facial expression, and gesture - Difficulty understanding or forming relationships - Repetitive motor movements, insistence on sameness, highly restricted interests - Unusual sensory responses (hypersensitivity or hyposensitivity)

Prevalence is approximately 1 in 36 children in the United States (CDC, 2023). Causes involve genetic factors (many genes, each of small effect) plus prenatal environment; the now-thoroughly-disproven vaccine hypothesis arose from a fraudulent 1998 study that was retracted and whose lead author lost his medical license.

Mascot-tip

Psy the Owl giving a tip Psy's AP Exam Tip: Know the two core diagnostic criteria for ASD (social-communication deficits + restricted/repetitive behavior). The vaccine-autism claim is definitively false — knowing this may be relevant for an experimental design or research methods question.

15.2 The Schizophrenia Spectrum¶

Schizophrenia is one of the most severe mental disorders — a breakdown in thought, perception, emotion, and the sense of self and reality. It affects approximately 1% of the global population and typically emerges in late adolescence or early adulthood.

Positive Symptoms¶

Positive symptoms of schizophrenia are symptoms that represent excesses or distortions of normal functioning — experiences present in schizophrenia that are absent in healthy individuals:

Hallucinations: False sensory perceptions occurring without an external stimulus. Auditory hallucinations (hearing voices) are most common; visual, tactile, olfactory, and gustatory hallucinations also occur.
Delusions: Fixed, false beliefs that are maintained despite contrary evidence and are not consistent with the person's cultural context. Common types include persecutory delusions ("people are following me"), grandiose delusions ("I am a prophet"), and delusions of reference ("the television is broadcasting messages specifically to me").
Disorganized thinking: Loose associations, thought blocking, tangential or incoherent speech.
Disorganized or catatonic behavior: Unpredictable agitation, inappropriate affect, catatonia (motionlessness or rigid posturing).

Negative Symptoms¶

Negative symptoms represent deficits or reductions in normal functioning — experiences that are present in healthy individuals but absent or diminished in schizophrenia:

Flat affect: Reduced emotional expression (blank face, monotone voice)
Alogia: Reduced speech quantity or content
Avolition: Reduced motivation for goal-directed activity
Anhedonia: Inability to experience pleasure
Asociality: Reduced interest in social interaction

Negative symptoms are harder to treat than positive symptoms. Antipsychotic medications that block dopamine receptors reduce positive symptoms effectively but have less impact on negative symptoms.

Diagram: Positive vs. Negative Symptoms of Schizophrenia¶

Explore: Why does the positive/negative distinction matter clinically?

Positive Symptoms (Add to experience) These represent added experiences not present in healthy functioning. They respond better to antipsychotic medications. - Hallucinations → false perceptions - Delusions → false beliefs - Disorganized speech/behavior → cognitive fragmentation

Negative Symptoms (Subtract from experience) These represent the loss of normal functions. They are harder to treat and more predictive of long-term functional impairment. - Flat affect → emotional blunting - Avolition → loss of motivation - Anhedonia → loss of pleasure - Alogia → poverty of speech - Asociality → withdrawal from others

Clinical implication: A person in remission from positive symptoms may still struggle significantly with negative symptoms — poor social function, reduced motivation, emotional blunting. The positive/negative distinction helps explain why medication alone is usually insufficient for functional recovery.

15.3 Anxiety Disorders¶

Anxiety disorders share the core feature of excessive fear or anxiety that is disproportionate to actual danger and impairs daily functioning. They are the most prevalent class of mental disorders.

Generalized Anxiety Disorder¶

Generalized Anxiety Disorder (GAD) is characterized by persistent, excessive, and difficult-to-control worry about multiple domains (work, health, family, finances) for at least six months, accompanied by physical symptoms such as restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance. The worry in GAD is pervasive — the person "catastrophizes" about daily events and cannot easily suppress the worry.

Agoraphobia¶

Agoraphobia is characterized by intense fear and avoidance of situations from which escape might be difficult or embarrassing if anxiety or panic occurred, or in which help might not be available. Feared situations include: crowds, public transportation, open spaces, enclosed spaces, standing in line, being outside the home alone. Many people with agoraphobia also have panic disorder (fear of the situations is linked to fear of having a panic attack in them).

Social anxiety disorder (social phobia) is characterized by intense fear of social situations in which the person might be scrutinized by others — fear of acting in a way that will be humiliating or embarrassing, or of offending others. Feared situations include: public speaking, eating in public, meeting new people, being observed. Social anxiety disorder is distinct from shyness (shyness is a personality trait; social anxiety disorder involves significant impairment).

Obsessive-Compulsive Disorder¶

Obsessive-Compulsive Disorder (OCD) is characterized by:

Obsessions: Persistent, intrusive, unwanted thoughts, images, or urges that cause significant anxiety (e.g., fear of contamination, intrusive thoughts of harming someone, need for symmetry)
Compulsions: Repetitive behaviors or mental acts performed to reduce obsession-related anxiety (e.g., hand washing, checking, ordering, counting)

Compulsions provide temporary relief but ultimately maintain the disorder by preventing the person from learning that the feared outcome would not occur (negative reinforcement of avoidance). OCD is ego-dystonic — the person recognizes the obsessions as irrational and does not want to have them — distinguishing it from normal worrying.

Treatment: Exposure and Response Prevention (ERP), a form of behavioral therapy in which the person is exposed to feared stimuli while being prevented from performing compulsions, is the gold standard. The person learns that the feared outcome does not occur, extinguishing the conditioned anxiety.

Hoarding Disorder¶

Hoarding disorder is characterized by persistent difficulty discarding possessions regardless of their actual value, resulting in accumulation that clutters living spaces and causes significant distress or impairment. Hoarding is distinguished from collecting (which is organized and not impair-functioning) by the disorganization, inability to discard, and functional impairment. Hoarding disorder was included as a separate diagnosis in DSM-5, having previously been classified as a symptom of OCD.

15.5 Personality Disorders¶

Personality disorders are enduring patterns of inner experience and behavior that deviate markedly from cultural expectations, are pervasive and inflexible, are stable over time, and lead to distress or impairment. They represent extremes or rigidities of personality traits.

Personality Disorder Clusters¶

The DSM organizes personality disorders into three clusters:

Cluster A — "Odd or Eccentric": - Paranoid: Pervasive mistrust and suspicion - Schizoid: Detachment from social relationships, restricted emotion - Schizotypal: Odd beliefs, magical thinking, social anxiety

Cluster B — "Dramatic, Emotional, or Erratic": - Antisocial personality disorder: Disregard for others' rights, deceit, impulsivity - Borderline personality disorder: Unstable relationships, self-image, affect, and impulsivity - Histrionic: Excessive emotionality and attention-seeking - Narcissistic: Grandiosity, need for admiration, lack of empathy

Cluster C — "Anxious or Fearful": - Avoidant: Social inhibition, feelings of inadequacy, hypersensitivity to criticism - Dependent: Submissive and clinging behavior, need to be taken care of - Obsessive-Compulsive: Preoccupation with orderliness, perfectionism, control

Antisocial Personality Disorder¶

Antisocial personality disorder (ASPD) is characterized by a pervasive pattern of disregard for and violation of the rights of others: deceit and manipulation for personal profit, impulsivity, irritability and aggressiveness, reckless disregard for safety, irresponsibility, and lack of remorse. ASPD requires evidence of conduct disorder before age 15. Psychopathy (not a DSM diagnosis but widely studied) adds shallow affect, superficial charm, and reduced empathy beyond ASPD.

Borderline Personality Disorder¶

Borderline personality disorder (BPD) is characterized by pervasive instability in mood, self-image, interpersonal relationships, and impulsive behavior. Features include: - Intense, unstable relationships (idealization to devaluation — "splitting") - Unstable self-image - Impulsive, self-damaging behavior - Suicidal or self-injurious behavior - Intense, rapid mood shifts - Chronic emptiness - Intense anger and difficulty controlling it - Transient paranoid ideation or dissociation under stress

BPD is highly associated with childhood trauma (particularly sexual abuse and early neglect). Dialectical Behavior Therapy (DBT) — a form of CBT modified for BPD — has strong evidence for reducing suicidal behavior and improving quality of life.

15.6 The Cognitive Perspective on Disorders¶

The cognitive perspective on disorders proposes that psychological disorders are maintained by distorted or dysfunctional patterns of thinking. Aaron Beck identified systematic cognitive errors (cognitive distortions) that characterize depression and anxiety:

All-or-nothing thinking: "If it's not perfect, it's a failure."
Catastrophizing: "This headache means I have a brain tumor."
Mind reading: "I know she thinks I'm incompetent."
Overgeneralization: "I failed this test; I always fail everything."
Selective abstraction: Focusing only on negative aspects while ignoring positives.

Beck proposed the cognitive triad of depression: negative views of the self ("I'm worthless"), the world ("The world is unfair"), and the future ("Nothing will ever get better"). These three negative cognition patterns maintain depressed mood and reduce motivation.

Cognitive therapy (Beck's specific approach) teaches clients to identify, challenge, and restructure these cognitive distortions through Socratic questioning, behavioral experiments, and thought records.

15.7 The Diathesis-Stress Model¶

The diathesis-stress model provides a unifying framework for understanding why not everyone who faces adversity develops a disorder. A diathesis is a pre-existing biological or psychological vulnerability — a genetic predisposition, early trauma, insecure attachment, or maladaptive thought patterns. Stress refers to environmental triggers — stressors that activate the vulnerability.

The model predicts that disorders emerge when diathesis meets sufficient stress. A person with high genetic vulnerability to depression may develop the disorder even under mild stress; a person with low vulnerability may remain healthy even under substantial adversity. This explains why trauma universally increases risk but does not universally produce disorder, and why family history is a risk factor but not a determinant.

15.8 Feeding and Eating Disorders¶

Feeding and eating disorders involve severe disruptions in eating behavior, related cognitions, and physiological regulation that impair health and functioning. Introduction is given here; detailed coverage of anorexia nervosa and bulimia nervosa appears in Chapter 16.

Key features shared by major eating disorders: - Intense preoccupation with weight, shape, or food - Significant functional impairment and health consequences - Typically onset in adolescence or early adulthood - More common in females but occur across genders - Driven by complex interactions of cultural ideals, perfectionism, and biological vulnerability

The sociocultural perspective is particularly important here: eating disorder prevalence tracks the spread of Western thin-ideal culture, is higher in cultures and subcultures emphasizing appearance and thinness, and can be created experimentally by exposure to idealized media images.

15.9 Psychotherapy Modalities¶

Psychodynamic Therapy¶

Psychodynamic therapy applies Freudian and neo-Freudian concepts to the therapeutic relationship. Goals include uncovering unconscious conflicts, resolving early developmental issues, and gaining insight into how past relationships influence present behavior. Techniques include free association (saying whatever comes to mind), dream analysis, and interpretation of transference (the client's displacement of feelings about past relationships onto the therapist). Contemporary psychodynamic therapies are shorter-term and more structured than classical psychoanalysis.

Behavioral Therapy¶

Behavioral therapy applies learning principles directly to the treatment of psychological disorders. The premise is that maladaptive behavior was learned and can therefore be unlearned or replaced through conditioning techniques:

Exposure therapy: Systematic, gradual, or intensive exposure to feared stimuli; extinguishes conditioned fear responses.
Systematic desensitization: A specific form of exposure therapy developed by Joseph Wolpe, pairing graduated exposure with relaxation. The client first learns deep relaxation, then creates an anxiety hierarchy, then gradually imagines (or encounters) feared stimuli while maintaining relaxation. The pairing of the feared stimulus with relaxation counteracts the conditioned fear response.
Contingency management: Modifying reinforcement contingencies to change problem behavior (used in substance use, ADHD, autism treatment).
Applied Behavior Analysis (ABA): Used intensively in autism intervention to build skills through reinforcement.

Humanistic (Person-Centered) Therapy¶

Humanistic (person-centered) therapy (Carl Rogers) provides the therapeutic conditions that allow clients to reconnect with their authentic self and realize their growth potential. The therapist offers:

Unconditional positive regard: Accepting the client without judgment.
Empathic understanding: Accurately reflecting the client's experience.
Congruence (genuineness): The therapist's genuine, authentic presence rather than a professional facade.

Person-centered therapy is non-directive — the therapist trusts the client's own growth drive and does not interpret, advise, or set agendas.

Cognitive Therapy¶

Cognitive therapy (Aaron Beck) focuses on identifying and modifying the distorted thought patterns that maintain psychological disorders. Working collaboratively with the client, the therapist helps identify cognitive distortions, examines evidence for and against dysfunctional beliefs, and gradually restructures core maladaptive schemas. Cognitive therapy combined with behavioral techniques produces cognitive-behavioral therapy (CBT) — the most empirically supported psychological treatment.

Group Therapy¶

Group therapy involves a therapist working simultaneously with multiple clients, typically 5–12 participants, often facing similar issues. Advantages include:

Social learning and modeling from peers
Universality — recognizing that others have similar struggles
Altruism — members helping each other builds self-esteem
Interpersonal feedback and skill practice
Cost-effectiveness

Group therapy is used for depression, anxiety, addiction, grief, trauma, and many other issues. Support groups (e.g., AA, NAMI) are related but peer-led, without a therapist.

Hypnosis in Treatment¶

Hypnosis is a state of heightened suggestibility, focused attention, and reduced peripheral awareness induced by a hypnotic induction procedure. In clinical settings, hypnosis is used as an adjunct to other treatments for pain management, anxiety, phobias, and habit change.

Hypnosis does not create special access to buried memories — contrary to popular belief, hypnotically retrieved "memories" are no more accurate than ordinary memories and may be more susceptible to suggestion. Its mechanisms appear to involve focused attention and expectation effects rather than a distinct altered state.

15.10 Ethnocentrism in Diagnosis¶

Ethnocentrism — applying one's own cultural standards as if they were universal — presents significant challenges in psychological diagnosis. The DSM and ICD were developed primarily in Western, educated, industrialized, rich, and democratic (WEIRD) societies and may reflect cultural assumptions that don't generalize.

Examples of cultural considerations in diagnosis: - Culture-bound syndromes: Patterns of distress specific to particular cultural contexts (e.g., ataque de nervios in Latino cultures, koro in Southeast Asia) that may not map onto DSM categories. - Normal vs. pathological: Grief rituals, spiritual experiences (visions, possession), and social behaviors that would qualify as psychotic or delusional in Western clinical contexts may be normal and valued in other cultural contexts. - Differential diagnosis across race: Research has documented racial disparities in diagnosis — Black patients are more likely to receive schizophrenia diagnoses and less likely to receive depression diagnoses than white patients with similar symptom profiles, reflecting cultural and racial bias in clinical assessment. - Help-seeking behavior: Cultural norms about expressing mental distress (stigma levels, idioms of distress, preferred help sources) vary widely and affect who seeks help and how they present.

The DSM-5's Cultural Formulation Interview and the development of culturally adapted evidence-based treatments represent efforts to address ethnocentrism in diagnosis and treatment.

15.11 Chapter Review¶

Mascot-celebration

Psy the Owl celebrating Outstanding work completing Chapter 15!

You've just surveyed the full range of psychological disorders and therapy approaches covered on the AP exam. This chapter and the next are often the most personally meaningful for students — most of us know someone (or are someone) who has experienced anxiety, depression, OCD, or another disorder covered here.

Chapter 16 is the final chapter — it covers the remaining disorders (PTSD, dissociative disorders, bipolar, eating disorders, panic disorder, MDD) and biological treatment (medications, ECT, TMS). You're almost there!