Download - Chapter 16 Schizophrenia
![Page 1: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/1.jpg)
Chapter 16
Schizophrenia
http://www.npr.org/programs/atc/features/2002/aug/schizophrenia/
![Page 2: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/2.jpg)
18.2 Treatment of the mentally ill
![Page 3: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/3.jpg)
• Schizophrenia
– A serious mental disorder characterized by disordered thoughts, delusions, hallucinations, and mood disturbance.
![Page 4: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/4.jpg)
Schizophrenia
• Positive Symptoms– Delusions– Hallucinations– Disorganized behavior
• Negative Symptoms– Social withdrawal– Mood disturbance– Reduced motivation
John Nash
© N
ajla
h F
ea
nn
y/C
OR
BIS
![Page 5: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/5.jpg)
• Schizophrenia–Positive symptoms
–Dopamine hypothesis:• Overactivity of dopamine in
mesolimbic pathway (VTA to nucleus accumbens and amygdala)
![Page 6: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/6.jpg)
• Schizophrenia– How are positive symptoms related to
dopamine?
– Hypothesis:• Mesolimbic system important for reinforcement of
behavior• We all have irrational thoughts, but usually brush
them aside• But if mesolimbic system was active when the
thought occurred, we might take it more seriously, leading to delusions
![Page 7: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/7.jpg)
– Hypothesis cont.:• Confirming piece of evidence:
schizophrenics often report euphoria at onset of positive symptoms
• Disordered thinking?– System so active that it does not discriminate
between thoughts, making it hard to follow a logical sequence
• Terrifying element of delusions?– Strong dopaminergic projection to amygdala
![Page 8: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/8.jpg)
Dopamine HypothesisEvidence for excessive dopamine
![Page 9: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/9.jpg)
• Dopamine agonists (cocaine, amphetamine, PCP) produce symptoms of psychosis.
• Dopamine antagonists reduce psychotic behavior.
• Patients may have abnormalities involving dopamine autoreceptors.
SchizophreniaPositive Symptoms
![Page 10: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/10.jpg)
• Schizophrenia– Positive Symptoms
– Chlorpromazine:• A “typical neuroleptic”
• A dopamine receptor blocker for D2 receptors
– Clozapine:• An “atypical neuroleptic”
• An antipsychotic drug that blocks D4 receptors in the nucleus accumbens
![Page 11: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/11.jpg)
• Tardive dyskinesia involves tremors and involuntary movements.
• Supersensitivity: increased sensitivity of neurotransmitter receptors (D2) to dopamine
• Due to side effects, about 50% now use atypical neuroleptics like clozapine.
Co
urt
esy
Da
vid
He
aly
, A
cad
em
y fo
r th
e S
tud
y o
f th
e
Psy
cho
an
aly
tic A
rts
SchizophreniaSide Effects of Typical Antipsychotics
![Page 12: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/12.jpg)
SchizophreniaSide Effects of Typical Antipsychotics
![Page 13: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/13.jpg)
Dopamine HypothesisEvidence for increase in D3 receptors
![Page 14: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/14.jpg)
Failure of Prepulse Inhibition in Schizophrenia
![Page 15: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/15.jpg)
Restoring Prepulse Inhibition in Schizophrenia
![Page 16: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/16.jpg)
Problems With a Excessive Dopamine Hypothesis• 25% of patients do not respond to dopamine
antagonists.
• Atypical antipsychotic medications (clozapine) act primarily on neurotransmitters other than dopamine.
• Drugs change dopamine activity immediately, but patient may not improve for weeks.
• PCP produces symptoms similar to schizophrenia by blocking the NMDA glutamate receptor.
![Page 17: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/17.jpg)
• Schizophrenia–Negative symptoms
–Brain damage:• Many of the negative symptoms are
also seen in people with frontal lobe damage
![Page 18: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/18.jpg)
Lifetime risks of developing schizophrenia
![Page 19: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/19.jpg)
Search for Brain AbnormalitiesEvidence for changes in ventricular size
Courtesy D.R. Weinberger, NIMH, St. Elizabeth’s Hospital, Washington, D.C.
![Page 20: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/20.jpg)
Disorganization of cells in the hippocampus
![Page 21: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/21.jpg)
Search for Brain AbnormalitiesLoss of gray matter with age
![Page 22: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/22.jpg)
Search for Brain AbnormalitiesLoss of gray matter with age
Cause of delay of onset??
![Page 23: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/23.jpg)
• Lower frontal lobe activity may account for the negative symptoms of schizophrenia.
• During rest (top) and an effortful cognitive test (bottom), patients with schizophrenia show less frontal lobe activity.
Co
urte
sy Dr. K
are
n F
. Be
rma
n, C
linica
l Bra
in D
isord
ers B
ran
ch,
NIM
H, N
IH
Hypofrontality in schizophrenia
![Page 24: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/24.jpg)
Hypofrontality in schizophreniaWisconsin Card Sorting Task
![Page 25: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/25.jpg)
Possible Causes of the Brain Abnormalities
– Seasonal effect– Latitude effect– Maternal exposure to viruses– Nutritional deficiency
• Hunger Winter study– Thiamine deficiency– Vitamin D deficiency (latitude effect?)
– Father’s age– Rh Incompatibility
![Page 26: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/26.jpg)
How are positive & negative symptoms related?
VTA
PrefrontalCortex
NA
DopamineHypoactivity(too little DA)
GABA neurons
Dopamine hyperactivity(too much DA)
![Page 27: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/27.jpg)
18.17 Schematic representation of the neurodevelopmental model of schizophrenia
![Page 28: Chapter 16 Schizophrenia](https://reader036.vdocuments.mx/reader036/viewer/2022062517/56649edb5503460f94beb387/html5/thumbnails/28.jpg)
18.16 A modified representation of the vulnerability–stress model