Schizophrenia Flashcards
On Exam 3 (Apr 22)
What is meant by “positive” symptoms of schizophrenia?
What symptoms fall into this category?
“Psychotic” symptoms characterized by a break with reality (having psychological experiences that other do not)
Includes hallucinations, delusions, and disorganized thoughts, speech, or behavior
What are hallucinations? What is the most common kind? Do they occur in the general population?
Perceptual experiences that occur without external stimuli
Most common is auditory, but they can affect any of the 5 senses
They’re fairly common in the general population (38%)
What are delusions? What are the common types?
Delusions are fixed false beliefs that are not amenable to change even when confronted with conflicting evidence
Common type is the paranoid delusion: believing that someone is trying to harm you despite little evidence to support that belief
Others: thought insertion, thought broadcasting, grandiose beliefs, control delusions, and bizarre delusions
What is disorganized behavior? What is catatonia?
Behavior that is disconnected from physical reality and seems random or dangerous
Sometimes has no clear rationale or delusional thought behind it
This includes catatonia: lack of response to what is happening in the environment, either via immobility or purposeless, repetitive behavior
What is meant by “negative” symptoms of schizophrenia?
What symptoms fall into this category?
The diminution of a part of a normal psychological experience that most people have (the absence of traits that we’d expect them to have)
Includes reduced emotional experience, avolition (decrease in self-directed behavior), alogia (decrease in speech output), less emotional expression in the face, and anhedonia
What is meant by “cognitive” symptoms of schizophrenia?
What symptoms fall into this category?
Cognitive impairments such as problems with: attention, inhibition of automatic behavior, performing simple mental tasks quickly, working memory, long-term verbal memory, social cognition
What is sensory gating?
The neurological process of filtering out unnecessary or repetitive environmental stimuli
Individuals with schizophrenia have a difficult time doing this
What aspects of the social environment can exacerbate the risk for schizophrenia or cause the worsening of symptoms?
Social stress, such as poor family communication and negative expressed emotion, can worsen symptoms and functional outcomes
What is the percentage of concordance for schizophrenia for MZ versus DZ twins?
What general conclusion can be drawn from the literature examining twin/adoption studies?
MZ: 30-50% of twins with schizophrenic relatives will develop schizophrenia
DZ: 12-17% of twins with schizophrenic relatives will develop schizophrenia
Conclusion: the more your genome resembles that of a family member with schizophrenia, the more likely you will be to develop the disorder yourself (schizophrenia is highly heritable, but not 100% controlled by genes)
What is a de novo mutation?
A spontaneous mutation that was not present in the parent’s DNA
Schizophrenia may develop from multiple rare genetic variants caused by these mutations, rather than inheriting the vulnerability directly from the parent
What two key pieces of evidence led researchers to focus on dopamine function as a component of schizophrenia?
1 - drugs that reduce dopamine activity diminish psychotic symptoms
2 - drugs that increase dopamine activity exacerbate psychotic symptoms
What research has suggested that the “too much dopamine” hypothesis is probably not valid?
Dopamine concentrations were not found to be markedly elevated in the brains of those with schizophrenia
What evidence is there to suggest the role of glutamate in schizophrenia?
Glutamate antagonists produce schizophrenia-like symptoms in people who use them, even more so than stimulants (dopamine agonists) do
What is the season-of-birth effect? What might explain it?
A disproportionate number of individuals with schizophrenia are born during winter
Disruptions caused by infections such as the flu and rubella during the second trimester, a critical developmental period, may lead to brain abnormalities that increase risk for schizophrenia
Exposure to these infections is often seasonal (late fall and early winter)
What is the difference between premorbid and prodromal symptoms?
Premorbid - subtle symptoms that occur long before the onset of schizophrenia
Eg: poor cognitive and social performance as a child + more negative facial expressions
Prodromal - symptoms that immediately precede the onset of psychotic symptoms
Eg: social withdrawal and suspiciousness
The authors draw a parallel between our understanding of schizophrenia and cancer – upon what basis do they make this analogy?
In both cases, they have no single biological cause. There is an interplay between biology and environmental factors, called a diathesis-stress model
What is a psychotic disorder?
Involves severe impairment in an individual’s perception or understanding of reality
What are illusions?
Misperceptions of something that’s actually there (unlike a hallucination, which is false perception)
How does schizophrenia impact affect, motivation, relationships, identity, and psychomotor behavior?
Affect: may be flat or they may experience mood lability (all over the place or inappropriate for the situation)
Volition: loss of motivation
Relationships: social withdrawal
Identity confusion: blurred boundaries between external and internal world
Motor: hyperactivity or rigidity
What is the criteria for a delusion?
Held with absolute conviction
Not changeable even when presented with a counterargument
Becomes the focus of thought and action
Implausible or patently untrue
What are bizarre vs non-bizarre delusions?
Non-Bizarre = theoretically possible but clearly untrue
Bizarre = violates the laws of nature
What are the 3 subtypes of Schizophrenia?
Paranoid: preoccupation with persecutory delusions or auditory hallucinations
Disorganized: disorganized speech and behavior + flat affect
Catatonic: motor immobility + wavy flexibility
What are some recent changes in the DSM-V with regards to Schizophrenia?
- Subtypes were removed because they weren’t a useful system anymore
- Greater number of symptoms required for diagnosis
- Presence of at least one “blatant” symptom
- New dimensional approach to rate severity of symptoms
What are some structural abnormalities correlated with Schizophrenia?
Increased volume of lateral ventricular areas (spaces filled with fluid)
Decreased brain volume, especially in frontal lobe and hippocampus
