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Unit 15: Psychological Disorders

How a pattern of thought or behavior crosses the line into a diagnosable disorder, and what's actually happening in the brain behind each major one.

12 topics · 41 questions

Each topic is a path, not a menu: work down it in order and every question builds on the one above. Click any of them to watch the answer draw itself.

15.1 What Counts as a Psychological Disorder

  1. How it worksHow do deviance, distress, dysfunction, and danger each factor into whether a pattern counts as a disorder?
  2. Going furtherWhat happens to whether a behavior counts as disordered as cultural norms around it shift over time?
  3. Common mistakeWhy isn't any unusual or eccentric behavior automatically a sign of a psychological disorder?
Your turn1 of 2
After the death of a close family member, someone experiences intense sadness, trouble sleeping, and low motivation for several weeks. A clinician does NOT immediately diagnose this as a psychological disorder. Using the criteria of deviance, distress, dysfunction, and danger, what likely explains this decision?

15.2 The DSM and Diagnostic Classification

  1. How it worksHow does the DSM organize disorders using specific criteria a patient's symptoms have to meet?
  2. Going furtherWhat happens to a diagnosis's usefulness when a patient's symptoms overlap the criteria for two different disorders at once?
  3. Common mistakeWhy isn't a DSM diagnosis meant to explain what caused a person's disorder in the first place?
  4. Worked exampleFind why two patients can both receive a major depressive disorder diagnosis while showing almost no overlapping symptoms.
Your turn1 of 2
Two patients both receive a diagnosis of major depressive disorder from the DSM, yet one patient's main symptoms are persistent sadness and sleep problems, while the other patient's main symptoms are loss of interest in activities and appetite changes, with almost no symptom overlap between them. How is this possible under the DSM's diagnostic system?

15.3 The Biopsychosocial Model of Mental Illness

  1. How it worksHow do biological, psychological, and social factors combine in the biopsychosocial model to explain a disorder?
  2. Going furtherWhat happens to a treatment plan's design when only the biological factor is addressed while the social factor is ignored?
  3. Common mistakeWhy isn't a purely biological explanation ever the complete story behind a psychological disorder?
Your turn1 of 2
A patient with depression is prescribed medication to address a suspected neurotransmitter imbalance, but their treatment plan completely ignores their profound social isolation and lack of any support network. According to the biopsychosocial model, what is the likely limitation of this treatment plan?

15.4 Generalized Anxiety and Panic Disorder

  1. How it worksHow does generalized anxiety disorder differ from a panic disorder in how the anxiety is spread out or concentrated?
  2. How it worksWalk me through the physical symptoms of a panic attack and what's actually happening in the brain during one.
  3. Common mistakeWhy isn't generalized anxiety disorder just an extreme version of everyday worry?
Your turn1 of 2
One person experiences a constant, free-floating sense of worry and anxiety about many different areas of life nearly every day, without any single specific trigger. A different person experiences sudden, intense episodes of overwhelming fear and physical symptoms that peak within minutes, occurring unpredictably, with calm periods in between. Which two anxiety-related disorders are being described, respectively?

15.4 Phobias and How They Form

  1. How it worksHow does classical conditioning explain a specific phobia forming from one bad experience?
  2. Worked exampleFind how a phobia of elevators, once formed, gets maintained by avoidance even after the original scare is long forgotten.
  3. Going furtherWhat happens to a phobia during exposure therapy, when avoidance is deliberately prevented?
  4. Common mistakeWhy doesn't every specific phobia trace back to an identifiable frightening experience?
Your turn1 of 2
Someone developed a phobia of elevators years ago after a bad experience, but they've long since forgotten most details of that original scary event. Even so, the phobia persists strongly today, since they've consistently avoided elevators ever since. How does this avoidance help explain why the phobia has lasted so long, even after the original memory faded?

15.5 Obsessive-Compulsive Disorder and the Brain's Worry Circuit

  1. How it worksHow does a specific brain circuit involving the orbitofrontal cortex and basal ganglia stay overactive in OCD?
  2. How it worksWalk me through how an obsession and a compulsion feed each other in a repeating cycle.
  3. Common mistakeWhy isn't OCD just being unusually neat or liking things in order?
Your turn1 of 2
Someone experiences a persistent, intrusive thought that their hands are contaminated with germs (an obsession), which creates intense anxiety. They then wash their hands repeatedly (a compulsion), which briefly relieves the anxiety, but the intrusive thought soon returns, restarting the cycle. What does this pattern illustrate about OCD?

15.6 PTSD and the Stress Response Gone Wrong

  1. How it worksHow does a traumatic memory get encoded so intensely that it later intrudes as a flashback?
  2. Going furtherWhat happens to the amygdala and hippocampus's activity in someone living with PTSD compared to someone without it?
  3. Worked exampleFind why a trigger as ordinary as a smell or a sound can be enough to reactivate a full trauma response in PTSD.
Your turn1 of 2
Years after returning from combat, a veteran experiences a full-blown panic response, complete with racing heart and a sense of being back in danger, triggered simply by the ordinary sound of a car backfiring. Why can such an everyday sound be enough to reactivate this intense trauma response?

15.7 Depressive and Bipolar Disorders

  1. How it worksHow do neurotransmitter imbalances relate to the persistent low mood and loss of interest seen in major depressive disorder?
  2. How it worksWalk me through how bipolar disorder cycles between depressive episodes and manic episodes.
  3. Common mistakeWhy isn't bipolar disorder just an extreme version of ordinary mood swings?
  4. Worked exampleFind which mood disorder better fits someone who cycles between weeks of extreme energy and weeks of deep depression.
Your turn1 of 2
Someone cycles between weeks of extremely high energy, minimal need for sleep, and grandiose ideas, followed by weeks of deep depression, low energy, and hopelessness. Which mood disorder does this pattern best fit?

15.8 The Symptoms and Brain Changes of Schizophrenia

  1. How it worksHow do positive symptoms like hallucinations differ from negative symptoms like flattened emotion in schizophrenia?
  2. How it worksWalk me through what excess dopamine activity is believed to do to perception in schizophrenia.
  3. Worked exampleFind the difference between a hallucination and a delusion using an example of each from schizophrenia.
Your turn1 of 2
One person with schizophrenia hears a voice commenting on their actions that isn't actually there. A different person with schizophrenia holds a firm, false belief that they are being secretly monitored by government agents, despite clear evidence against it. Which symptom, a hallucination or a delusion, does each person show, respectively?

15.8 Why Schizophrenia Isn't Split Personality

  1. How it worksHow does schizophrenia's break from reality differ entirely from having multiple distinct personalities?
  2. Common mistakeWhy isn't schizophrenia the same disorder as what's now called dissociative identity disorder?
  3. Going furtherWhat happens to public understanding of schizophrenia when media confuses it with a split personality?
  4. Worked exampleFind which disorder, schizophrenia or dissociative identity disorder, actually involves separate identities taking control of behavior.
Your turn1 of 2
One disorder involves a break from shared reality, including hallucinations and delusions, but a single, continuous identity throughout. A different, much rarer disorder involves distinctly separate identities that can each take control of a person's behavior at different times, often with memory gaps between them. Which disorder, schizophrenia or dissociative identity disorder, actually involves these separate identities?

15.9 Dissociative Identity Disorder and Dissociative Amnesia

  1. How it worksHow does severe, repeated childhood trauma get linked to the later development of dissociative identity disorder?
  2. Going furtherWhat distinguishes dissociative amnesia from ordinary forgetting or from a physical brain injury?
  3. Common mistakeWhy isn't dissociative identity disorder the same thing as schizophrenia, despite the two being confused in casual speech?
  4. Worked exampleFind why a person with dissociative amnesia can forget their entire identity while still remembering how to drive a car.
Your turn1 of 2
A person with dissociative amnesia suddenly cannot recall their own name, family, or personal history, yet they can still drive a car, use utensils to eat, and speak fluently without any noticeable difficulty. What does this pattern of what's lost versus what's retained suggest?

15.10 Childhood and Personality Disorders

  1. How it worksHow does ADHD's difficulty with attention and impulse control show up differently at different ages?
  2. How it worksWalk me through how a personality disorder like antisocial personality disorder involves a lifelong, inflexible pattern rather than an occasional episode.
  3. Going furtherWhat makes autism spectrum disorder a spectrum rather than a single fixed set of symptoms?
Your turn1 of 2
A child with ADHD struggles intensely to sit still and stay focused during a structured classroom lesson, but shows sustained focus and calm engagement for over an hour while playing with an interesting set of building toys at home. What does this difference across settings suggest about ADHD?