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Questions and Answers
What is a defining feature of schizophrenia?
What is a defining feature of schizophrenia?
What distinguishes negative symptoms of schizophrenia?
What distinguishes negative symptoms of schizophrenia?
Which of the following is a misconception about schizophrenia?
Which of the following is a misconception about schizophrenia?
Which symptom type includes irrational beliefs or paranoia?
Which symptom type includes irrational beliefs or paranoia?
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What is the primary risk associated with untreated schizophrenia?
What is the primary risk associated with untreated schizophrenia?
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Which of the following best describes cognitive symptoms in schizophrenia?
Which of the following best describes cognitive symptoms in schizophrenia?
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How often does schizophrenia affect people in North America?
How often does schizophrenia affect people in North America?
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Which is necessary for a diagnosis of schizophrenia according to DSM-5?
Which is necessary for a diagnosis of schizophrenia according to DSM-5?
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What does the 'two-hit hypothesis' suggest about the development of schizophrenia?
What does the 'two-hit hypothesis' suggest about the development of schizophrenia?
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Which of the following factors is NOT correlated with the development of schizophrenia?
Which of the following factors is NOT correlated with the development of schizophrenia?
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What anatomical feature is commonly observed in the brains of individuals with schizophrenia?
What anatomical feature is commonly observed in the brains of individuals with schizophrenia?
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What is a possible consequence of enlarged lateral ventricles in individuals with schizophrenia?
What is a possible consequence of enlarged lateral ventricles in individuals with schizophrenia?
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Which neuroanatomical change is associated with schizophrenia at a microscopic level?
Which neuroanatomical change is associated with schizophrenia at a microscopic level?
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What does the enlargement of lateral ventricles typically leave behind?
What does the enlargement of lateral ventricles typically leave behind?
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Which prenatal infection is specifically mentioned as potentially damaging to the fetal brain?
Which prenatal infection is specifically mentioned as potentially damaging to the fetal brain?
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What type of brain pathology is NOT characterized in individuals with schizophrenia?
What type of brain pathology is NOT characterized in individuals with schizophrenia?
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What is often observed in the brains of patients with schizophrenia?
What is often observed in the brains of patients with schizophrenia?
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What significant correlation exists in patients with schizophrenia regarding hippocampal volume?
What significant correlation exists in patients with schizophrenia regarding hippocampal volume?
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Which drug was a major advancement in the treatment of schizophrenia?
Which drug was a major advancement in the treatment of schizophrenia?
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What unique property do antipsychotic drugs such as chlorpromazine possess?
What unique property do antipsychotic drugs such as chlorpromazine possess?
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What was a consequence of the discovery of chlorpromazine in the treatment of schizophrenia?
What was a consequence of the discovery of chlorpromazine in the treatment of schizophrenia?
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How were the neurons in the hippocampus of patients with schizophrenia found to be in post-mortem samples?
How were the neurons in the hippocampus of patients with schizophrenia found to be in post-mortem samples?
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Young patients exhibiting first symptoms of schizophrenia show what characteristic in terms of hippocampal size?
Young patients exhibiting first symptoms of schizophrenia show what characteristic in terms of hippocampal size?
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Chlorpromazine belongs to which class of drugs?
Chlorpromazine belongs to which class of drugs?
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What is the typical age range when schizophrenia is usually diagnosed?
What is the typical age range when schizophrenia is usually diagnosed?
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What are common prodromal symptoms of schizophrenia?
What are common prodromal symptoms of schizophrenia?
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Which factor is associated with a better prognosis for recovery from schizophrenia?
Which factor is associated with a better prognosis for recovery from schizophrenia?
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How long is the typical lag time between the first onset of symptoms of schizophrenia and diagnosis?
How long is the typical lag time between the first onset of symptoms of schizophrenia and diagnosis?
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What is the relative risk of developing schizophrenia for identical twins?
What is the relative risk of developing schizophrenia for identical twins?
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What percentage of individuals experiencing treatment for schizophrenia typically go through relapse and recovery?
What percentage of individuals experiencing treatment for schizophrenia typically go through relapse and recovery?
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What common psychological experiences can occur during the prodromal stage of schizophrenia?
What common psychological experiences can occur during the prodromal stage of schizophrenia?
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In fraternal twins, what percentage of shared genetics could be a factor for developing schizophrenia if one twin has the condition?
In fraternal twins, what percentage of shared genetics could be a factor for developing schizophrenia if one twin has the condition?
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What effect does haloperidol have on dopamine D2 receptors in the striatum?
What effect does haloperidol have on dopamine D2 receptors in the striatum?
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How do stimulant drugs like cocaine and amphetamine affect psychotic symptoms in users?
How do stimulant drugs like cocaine and amphetamine affect psychotic symptoms in users?
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What condition is characterized by under-stimulation of dopamine D1 receptors in the prefrontal cortex in individuals with schizophrenia?
What condition is characterized by under-stimulation of dopamine D1 receptors in the prefrontal cortex in individuals with schizophrenia?
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What is the proposed ideal treatment for schizophrenia regarding dopamine receptors?
What is the proposed ideal treatment for schizophrenia regarding dopamine receptors?
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Which neurotransmitter is primarily associated with the excitatory functions in the context of schizophrenia?
Which neurotransmitter is primarily associated with the excitatory functions in the context of schizophrenia?
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What role does GABA play in relation to glutamate in the context of schizophrenia?
What role does GABA play in relation to glutamate in the context of schizophrenia?
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Which of the following symptoms are potentially alleviated by blocking dopamine D2 receptors in individuals with schizophrenia?
Which of the following symptoms are potentially alleviated by blocking dopamine D2 receptors in individuals with schizophrenia?
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What is one hypothesized consequence of dopamine overactivity in individuals with schizophrenia?
What is one hypothesized consequence of dopamine overactivity in individuals with schizophrenia?
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What was one significant effect of chlorpromazine's discovery in psychiatry?
What was one significant effect of chlorpromazine's discovery in psychiatry?
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Which neurotransmitter system does chlorpromazine primarily affect in treating psychosis?
Which neurotransmitter system does chlorpromazine primarily affect in treating psychosis?
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What is the main mechanism by which antipsychotics like chlorpromazine function?
What is the main mechanism by which antipsychotics like chlorpromazine function?
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Which part of the brain is considered most important in the context of schizophrenia and dopamine D2 receptors?
Which part of the brain is considered most important in the context of schizophrenia and dopamine D2 receptors?
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What type of imaging technique is PET?
What type of imaging technique is PET?
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Which part of the striatum is involved in reward learning and motivation?
Which part of the striatum is involved in reward learning and motivation?
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What characterizes the positive symptoms of schizophrenia?
What characterizes the positive symptoms of schizophrenia?
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What is a characteristic feature of the dorsal striatum?
What is a characteristic feature of the dorsal striatum?
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Study Notes
Schizophrenia Overview
- Schizophrenia is classified as a psychotic disorder
- Psychosis involves a loss of contact with reality.
- Approximately 1/100 people in North America are affected.
- The estimated annual cost of schizophrenia in the U.S. is around $60 billion, largely due to treatment and lost wages.
- It's a common disorder with severe consequences for patients and their loved ones.
Myths about Schizophrenia
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Myth: People with schizophrenia are violent and dangerous.
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Fact: Individuals receiving treatment are not more violent than others. Untreated individuals, however, are most at risk of harming themselves.
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Myth: People with schizophrenia have multiple personalities.
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Fact: Schizophrenia is not the same as multiple personality disorder.
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Myth: People with schizophrenia see things that aren't there.
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Fact: Auditory hallucinations are a major symptom, while visual hallucinations are less common.
Characteristics of Schizophrenia
- Positive symptoms: experiences beyond normal: hallucinations (auditory most common), and delusions (irrational beliefs or paranoia misrepresenting reality, i.e., erotomanic delusions).
- Negative symptoms: deficits or absence of normal behavior: apathy, limited thought/speech, emotional or social withdrawal.
- Cognitive symptoms (disorganized): erratic changes in speech, motor behavior, and emotions (e.g., disorganized speech, inappropriate emotional reactions).
DSM-5 Diagnostic Criteria
- Individuals must have at least one of the following: delusions, hallucinations, or disorganized speech.
- Symptoms must be present for a significant portion of a one-month period, or less if treated effectively.
Development of Schizophrenia
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Usually diagnosed during late adolescence or early adulthood.
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A period of 1-2 years often exists between the first onset of symptoms and diagnosis.
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85% of cases have a prodromal stage: a 1-2-year period with subdued symptoms.
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Common prodromal symptoms: magical thinking, minor illusions (feeling of presence when alone), and ideas of reference.
Development and Prognosis
- Complete remission is rare, with most people experiencing relapse and recovery.
- Prognosis is poorer compared to other disorders, but more favorable with:
- Good social adjustment before onset.
- Low proportion of negative symptoms.
- A strong social support system.
- Symptoms may decrease with age or "level out".
Etiology - Genetics
- Schizophrenia has a genetic component (approximately 40% heritability).
- The risk is higher for identical twins than fraternal twins.
- Involved genes affect dopamine function, among others.
Etiology - Perinatal Factors
- Prenatal problems, shortly after birth, can increase schizophrenia risk.
- Environmental stressors impacting development can activate a predisposition.
- Viral/infectious exposure (e.g., influenza, Toxoplasmosis gondii) in the womb might impact fetal brain development, leading to schizophrenia symptoms later.
- Pregnancy/delivery complications might also increase risk.
- Prenatal nutrition or stress might play a role, like the Dutch Hunger Winter.
Anatomical Basis of Schizophrenia
- Enlarged lateral ventricles. Ventricle size, reflecting brain tissue, is a factor.
- Reduced dendritic spine density in the prefrontal cortex. Dendritic spines are small knobs on dendrites representing post-synaptic terminals.
- Reduced hippocampal volume, correlated with illness severity.
- Disorganized neurons in the hippocampus.
Antipsychotic Drugs
- Chlorpromazine, discovered in the 1950s, was a revolutionary antipsychotic drug, diminishing agitation and allowing for a return to normal life.
- Antipsychotics work mainly by blocking dopamine receptors, specifically D2 receptors (D2 antagonists).
Methods Minute: Positron Emission Tomography (PET)
- PET is an imaging technique that detects changes in blood flow and compound uptake.
- Radioactively labeled molecules track glucose or oxygen uptake, revealing metabolic activity in the brain regions.
Anatomy Minute: The Striatum
- The striatum is part of the basal ganglia involved in habit learning, motor and action planning.
- The dorsal striatum participates in habit learning, as well as planning.
- The ventral striatum, aka nucleus accumbens, participates in reward learning, motivation.
Symptoms of Schizophrenia Relate to Overstimulation of D2 Receptors
- Dopamine D2 receptors in the striatum are critical for schizophrenia, especially positive symptoms linked to excessive stimulation.
- Radioactive dopamine ligand (11C-NMSP) binding in the striatum can be diminished by antipsychotics, such as haloperidol.
Further Evidence for Dopamine's Role
- Cocaine and amphetamine can induce psychosis due to increased dopamine, supporting the role in psychosis.
- Drugs to decrease dopamine signaling might reduce psychosis.
More About Dopamine
- Hypofrontality: Under-stimulation of dopamine D1 receptors in the prefrontal cortex in some schizophrenia cases can impact planning, problem-solving and sophisticated reasoning.
- Researchers are searching for a drug that blocks D2 but activates D1 receptors in this context.
But Wait - There's More! (Glutamate Hypofunction)
- Glutamate and GABA imbalances affect the neuronal network; the balance impacts cognition and negative symptoms and impacts synaptic pruning.
- Synaptic pruning is the removal of extra synapses, critical in brain development and is impacted differently in adolescence in schizophrenia cases compared to neurotypical brains.
- Immune factors, alongside glutamates, impact brain development and potentially underlay schizophrenia’s neurodevelopmental aspects.
Summary (Neuroscience of Schizophrenia)
- Schizophrenia has a genetic component (40% heritability), impacting neurodevelopment.
- Excess dopamine activity in subcortical regions links to positive symptoms (delusions, hallucinations).
- Reduced dopamine in the frontal cortex can cause cognitive problems.
- Glutamate/GABA imbalance impacts motivation and cognitive functions.
- Abnormal brain development, especially excessive synaptic pruning in adolescence, aligns with the "two-hit" hypothesis.
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Test your knowledge of schizophrenia with this comprehensive quiz. Explore key features, symptoms, misconceptions, and neuroanatomical changes associated with this mental health disorder. Perfect for students and professionals alike.
