Chapter 9: Schizophrenia Flashcards
1
Q
What are the main characteristics of schizophrenia?
A
- positive symptoms
→ hallucinations and delusions - negative symptoms
→ emotional withdrawal and lack of motivation - overall adverse changes in thought, perception, emotion, and motor behaviour, and a feeling of depersonalization
- heterogeneity
2
Q
What is heterogeneity?
A
- variability and diversity of clinical and biological features seen in schizophrenia
3
Q
What is the lifetime risk of developing schizophrenia?
A
- 1%
4
Q
When is schizophrenia most frequently manifested?
A
- 20 and 40 years of age
5
Q
What is the gender difference in schizophrenia?
A
- equal risk
- men display symptoms earlier and more severely
6
Q
What is the prognosis of individuals with schizophrenia?
A
- less likely to complete education
- less likely to maintain a job
- more likely to develop additional psychiatric problems (depression, alcohol abuse)
7
Q
What has been the historical view of schizophrenia?
A
- existed under other names and description, such as madness or lunacy
- auditory hallucinations, which occur in about 70% of schizophrenia patients, were rarely described in cases prior to the 1700s
- extremely rate until the late eighteenth century
- speculated that industrialization and environmental changes may be related to this emergence
8
Q
What are the phases of schizophrenia over a lifetime?
A
- premorbid phase
→ no symptoms or impaired social competence
→ mild cognitive disorganization or perceptual distortion
→ anhedonia
→ mild and recognized only in retrospect - prodromal phase
→ subclinical symptoms may emerge
→ negative symptoms
→ withdrawal or isolation, irritability, suspiciousness, unusual thoughts, perceptual distortions, and disorganization
→ onset of overt schizophrenia (delusions and hallucinations) may be sudden (over days or weeks) or slow and insidious (over years).
- middle/active phase → positive symptoms → symptomatic periods episodic (with identifiable exacerbations and remissions) or continuous → functional deficits tend to worsen → treatment and relapse
- late illness/static/residual phase
→ illness pattern may be established
→ disability may stabilize or even diminish
9
Q
What are the three main symptom clusters in schizophrenia?
A
- positive
- negative
- cognitive (sometimes subdivided into the two above)
10
Q
What are positive symptoms?
A
- additions to mental life in excess of normal function
- include more obvious symptoms of psychosis
→ hallucinations, delusions, disordered thought, grossly disorganized catatonic behaviour
11
Q
What are hallucinations?
A
- false perception in the absence of any relevant sensory stimulus
- aka sensing something that isn’t there
- can occur in any sense modality
→ auditory and tactile most commonly occurring
→ visual generally only during early stages
12
Q
What are delusions?
A
- false beliefs that have no basis in reality
→ usually involve misinterpretation of perceptions or experiences
→ held with extraordinary conviction and subjective certainty
→ not affected by rational argument or evidence to the contrary
- most commonly persecutory → referential (thinking something refers to you, "the TV is talking to me" etc.) → somatic → religious → grandiose
13
Q
What is disorganized speech?
A
- nonsensical speech often signals the presence of thought disorder
- shows loosening of associations and logical connections between ideas or words
14
Q
What are negative symptoms?
A
- feature of schizophrenia showing behavioural deficits, a lack of normal functioning
→ sparse speech and withdrawal → affect flattening → avollition → anhedonia → alogia → asociality
15
Q
What is affect flattening?
A
- lack of emotional expression and response
16
Q
What is avolition?
A
- lack of initiation of goal-directed behaviours
17
Q
What is alogia?
A
- restrictions in fluency and productivity of thoughts and speech
18
Q
What is grossly disorganized behaviour?
A
- motor symptom of schizophrenia
- difficulty in goal-directed behavior (leading to difficulties in activities in daily living)
- unpredictable agitation or silliness
- social disinhibition, or behaviors that are bizarre to onlookers
- purposelessness distinguishes them from unusual behavior prompted by delusional beliefs.
19
Q
What is catatonic behaviour?
A
- motor symptom of schizophrenia
- marked decrease in reaction to the immediate surrounding environment
→ motionless and apparent unawareness
→ rigid or bizarre postures
→ aimless excess motor activity.
20
Q
What is waxy flexibility?
A
- state wherein a person’s limbs and posture can be “moulded” into different positions
21
Q
What are examples of cognitive impairments resulting from schizophernia?
A
- Disorganized thought process
- Disorganized speech → incoherence → loose associations → neologisms → poor verbal fluency (word salad) → excessive concreteness
- impaired attention and information processing
→ problems concentrating - impaired vigilance in executive functioning → prioritizing and impulse control
22
Q
What are the three forms of disorganized thought in schizophrenia?
A
- Thought insertion
→ belief that thoughts from other people are being inserted into one’s mind - Thought withdrawal
→ belief that thoughts have been removed from one’s mind by an outside agency - Thought broadcasting
→ belief that one’s thoughts can be heard by others
23
Q
What are neologisms?
A
- words a person makes up that have meaning only for that person
→ often part of a delusional system
24
Q
What is clang association?
A
- meaningless rhyming of words, often in a forceful manner
25
How do people with schizophrenia experience attention problems?
- exaggerated distractibility, intrusion of ideas, and mind wandering
- perception is intensified
→ interaction of distractibility with intrusive experience =
problems with attention
26
How is attention measured in tests for those with schizophrenia?
- reaction time (RT)
→ better time with short prep interval
→ poor time with long prep interval (distractibility)
- apprehension span (detecting target stimulus in an array)
→ more complex arrays yield poorer results
- smooth pursuit eye movement
→ irregular SPEM in schz
27
What are the diagnostic criteria for schizophrenia?
* Must have major disruption to function
* Symptoms present for at least 6 months
* Include at least 1 month of active (positive) symptoms
* DSM 5 requires 2 instead of 1 symptom and gets rid of most subtypes, though can now offer ‘specifiers’ to add some detail to the diagnosis (e.g., catatonia)
• At least two of the following:
– (one of which must be delusions, hallucinations or disorganized speech),
– grossly disorganized or catatonic behavior,
– negative symptoms
28
What are some issues with diagnosing schizophrenia?
- distinguish between bizarre delusions and those that are mood congruent
→ may be mood disorder rather than schizoprenia spectrum disorder
- diagnosis reliant on patient's presenting symptoms and history as main indication
→ results in subjectivity
29
What has been proposed about potential cognitive subtypes of schizophrenia?
- subgroups have been identified based on impairment in problem solving, eye tracking, as well as in terms of memory deficits
30
Why has it been important to define subtypes in schizophrenia?
- objective diagnosis is possible if measurable disease markers that occur in virtually all people with the illness can be identified
- markers could be psychological, physical, or biological characteristic or trait
→ should have sensitivity and specificity for the disease
31
What is the social class-illness link in schizophrenia?
- cumulative exposure to poverty, crime and family disturbance led to increased cases of schizophrenia
32
What are the prenatal environmental risk factors of schizophrenia?
- complications during birth may cause brain dysfunction/damage
(e. g., nutritional)
- obstetrical/birth complications
(e. g., Caesarean section, anoxia at birth)
- season of birth
→ higher during winter/spring
→ prenatal virus exposure (influenza virus exposure during second trimester)
→ Vitamin D deficiency
33
How does culture affect schizophrenia?
- cross-cultural consistency
- improved prognosis in developing countries
- family dynamics affect prognosis
→ e.g., expressed emotion (criticism, hostility, over-involvement)
34
What does Meehl's theory propose about the causes of schizophrenia?
- stress-diathesis model
- diathesis stress present called hypokrisia
→ hypersensitivity of nerve cells in the brain to incoming stimulations
- hypokrisia causes cognitive slippage
→ information becomes incoherent and causes thought disturbance
→ brain amplifies feelings of pain and weakens pleasure
→ aversive drift or withdrawal for interpersonal relationships
35
What is cognitive slippage?
- mental consequence of hypokrisia
| - loss of integrated thinking and coherent mental life
36
What is aversive drift?
- in Meehl's theory, tendency for people with a genetic predisposition for schizophrenia to be perceived negatively and subjected to personal rejection
→ leads to progressive social withdrawal and alienation
37
What is penetrance?
- percentage of people with a given genetic endowment who actually express the effects of the endowment
38
How is genetics related to schizophrenia?
Family Studies
– inherit a tendency for schizophrenia, not a specific form of schizophrenia
Twin Studies
– concordance is related to severity - higher concordance when one twin has severe SCHZ
– higher heritability when looking only at negative symptoms (regardless of positive symptoms)
Adoption Studies
– Risk of schizophrenia remains high in adopted children with a biological parent suffering from schizophrenia
39
What brain abnormalities are associated with schizophrenia?
- frontal lobe regions
→ show deficiency in activation
- left temporal lobe
- amygdala and hippocampus
- fluid-filled ventricles larger in patients with schizophrenia
40
What neurotransmitter is mostly associated with schizophrenia?
- abnormal activity of dopamine
41
What is the neurodevelopmental hypothesis of schizophrenia?
- may originate from abnormalities in fetal brain development
```
- genetic or acquired insults may lead to
→ inadequate neuronal selection
→ poor cell migration
→ aberrant synapse formation
→ faulty connections
```
- abnormalities may lie dormant for childhood years and reveal themselves only after adolescent restructuring
of the brain
42
What is the pattern of cell loss in schizophrenia patients?
- occur suddenly during late adolescence or early adulthood
- loss of dendrites
→ areas of tissue loss are correlated with symptoms
→ e.g., temporal lobes with auditory hallucinations
→ NOT cell death with gliosis (replacement of neural tissue by glia)
- frontal cortex seems to be involved in most cases
43
What is the prefrontal cortex hypothesis?
- frontal cortex important to decision making, among other cognitive facilities
- one of last brain areas to mature is the dorsolateral prefrontal cortex
→ developmental insult results in hypofrontality
- evidence of this in reduced gray matter over time
→ less functional activity in pfc related to negative symptoms
→ impairment in attention tests due to reduced executive function
44
What is hypofrontality?
- state of decreased cerebral blood flow (CBF) in the prefrontal cortex of the brain during tests of executive function (but not at baseline)
45
How is dorsolateral prefrontal cortex (DLPFC) impairment related to schizophrenia?
- reduced activation of the dorsolateral prefrontal cortex during a context processing/attention task for schizophreniac patients
46
What is the glutamatergic dysfunction hypothesis of schizophrenia?
- glutamatergic neurons represent the primary excitatory afferent and efferent systems innervating the cortex, limbic regions, and striatum
- developed from the observed effects of mind-altering drugs
- NMDA antagonists mimic some positive and negative symptoms with less brain harm
- overactivation of systems can lead to altered synaptic connectivity and cell death
- underactivation of systems alters migration, synaptic organization and cell survival
47
What is the hypofrontality theory of schizophrenia?
- Vulnerability in the prefrontal cortex
- DA neurons underactive in the PFC mesocortical dopamine system
→ Negative symptoms
+ Mesolimbic dopamine system is out of inhibitory control
→ Positive symptoms
48
What is chlorpromazine?
- first genuine antipsychotic medication
- thought to be useful in treating mood disorders, mania, and agitation
- discovered that antipsychotic properties required several weeks of treatments to take effect
49
What newer and improved medications were invented to treat schizophrenia?
- risperidone
| - olanzapine
50
What biological treatments are used to treat schizophrenia?
- phenothiazines, or neuroleptics
- about 25% do not respond
- successful treatment accompanied by side effects
→ grogginess, depression, akinesia, and akathesis
→ tardive dyskinesia
- clozapine and other "atypical" antipsychotics show hope
51
How does CBT help treat schizophrenia?
- reduce severity or frequency of psychotic symptoms
→ greatest effects in reducing negative symptoms
- focus on the interaction of personal vulnerability and stressful circumstances in the production of delusions, hallucinations, and negative symptoms
→ attention to the relations between thoughts, feeling and behaviours
52
How does social skills training help treat schizophrenia?
- learning-based intervention model for the treatment of functional disabilities associated with schizophrenia
53
What behavioural and social interventions are used to treat schizophrenia?
- operant conditioning
- modelling
- token economies
- self-help groups
54
What are assertive community treatment programs?
- integrated and comprehensive community-based programs
| → esp for those who might not have family support
55
How does family therapy help treat schizophrenia?
- combines education with training in coping strategies
- focus on better communication strategies, problem-solving skills, and behavioural strategies for encouraging appropriate
behaviours
- aims at the active involvement of the family in the therapeutic process.
56
What is risperidone?
- "atypical" antipsychotic
| - believed to work on serotonin as well as dopamine
57
What makes an antipsychotic "atypical"?
- less likely than the most widely used typical antipsychotic haloperidol to cause extrapyramidal motor control disabilities in patients
- lower risk of tardive dyskinesia in vulnerable clinical populations at doses that produce comparable control of psychosis
- different mechanism of action
58
What do antipsychotic medications generally do?
- block receptors in the brain's dopamine pathways
