Week 1 - Coursera: Schizophrenia (Wesleyan University) PDF

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Coursera: Schizophrenia (Wesleyan University)...

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Schizophrenia: Week 1 Introduction to Schizophrenia ● ● ● ● ● ●

The psychology of the disorder The neuroscience of the disorder Studies regarding treatment of the disorder Current approaches to understanding the disorder and its treatment Understanding the academic study of schizophrenia as it defined by the ICD-10 Common Misconceptions ○ The idea that schizophrenia involves split personalities ○ People with schizophrenia are highly violent

Louis Wain’s cat ● ● ●

He was a popular illustrator in the late 1800s early 1900s in Great Britain. He was well known for his “anthropomorphized cats” paintings. In his 20s and 30s, he started developing some unusual symptoms… ○ He had a delusion that electricity was being placed directly from the movie into his brain. ○ In some drawings, he makes cats look hard to recognize, which may represent his actual visual perception.

Prevalence, Demographics, and Etiology ●

Epidemiology of Schizophrenia ○ About 1% prevalence in the population ○ Occurs in all cultures, all socioeconomic groups ○ Peak onset in men, age 15 to 25 ○ Peak onset in women, age 25 to 35 ○ Prevalence often thought to be higher in men than women ○ 50% of patients attempt suicide, 10% succeed ○ Most expensive of all mental disorders: ■ Direct costs = 0.4% of the GNP ■ Indirect costs = 1.6% of the GNP

Gender Differences ● ●

Women are more likely to have a relative with the disorder, to experience more positive symptoms to have a better treatment response. Men have more negative symptoms, earlier onset, and worse long-term outcome.

Etiology of Schizophrenia ●

Genetics Table 1.1 Relationships between genetics and the risk of getting schizophrenia

No Genetic Relationship (Base Rate)

My risk of getting it is:

My chances of not getting it are:

Schizophrenia Bipolar Disorder Panic Disorder OCD Major Depression

1% 1.2% 1.6% 2~3% 5%

99% 98.8% 98.4% 97~98% 95%

First Degree Relatives

My risk getting it is:

My chances of not getting it are:

My brother or sister has: Schizophrenia Bipolar Disorder Depression

10% 12% 15%

90% 88% 85%

One of my parents has: Schizophrenia Depression Bipolar Disorder

13% 15% 27%

87% 85% 73%

Both my parents have: Schizophrenia Bipolar Disorder

37~46% 74%

54~63% 26%

My identical twin has: Schizophrenia Major Depression Bipolar Disorder

35~50% 59% 74~80%

50~65% 41% 20~26%

Table 1.2 The Risk of Developing a Schizophrenic Disorder Relationship

Identical Twins

Siblings, Fraternal One schiz. twins parent parent schiz.

Sibling

Nephew/ Spouse niece

Unrelate d people

Chance of being schizophrenia (%)

46

46

10

3

1

14

13

2

Environment ●

Diathesis-Stress Model ○ Ex. The study of children born to mothers suffered through the Hunger Winter in Holland in the early 1940s. ○ Maternal stress during pregnancy may lead to higher rates of schizophrenia in the children who were born. Figure 1.1 Diathesis-Stress Model

Figure 1.2 Diathesis-Stress Model (Alcoholism)

Symptoms of Schizophrenia: Positive, Negative, and Disorganization ●

Positive Symptoms of Schizophrenia ○ Positive schizophrenia symptoms involve excesses or distortions ■ Hallucinations are sensory experiences that occur in the absence of environmental stimulation (Hear or see things don’t exist) ■ Hallucinations are commonly auditory ■ Delusions are beliefs that contrary to reality (Believe things that are not real) ● Persecutory delusions are common

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Types of Delusions ○ Grandiose Delusions: ■ Thinking you have special powers. ■ Thinking you are someone powerful or famous. ■ Thinking you can control others just by thinking ● Ex. A patient believes they are Jesus. ○ Paranoid Delusions: ■ Thinking people plan to hurt or cheat you ■ Thinking people are against you ■ Thinking people are sick or dying ■ Thinking catastrophes will happen ● Ex. The devil made my boss fire me. ○ Delusions of Reference: ■ Thinking others are talking about you ● Ex. Believing you have received special messages from the TV or radio. ○ Semantic Delusion: ■ A false belief about your body. ● Ex. Thinking your heart had stopped working. ○ Delusions of Being Controlled: ■ Thinking of others or an external force controls your feelings, thoughts, actions, or behaviors. ● Ex. Believing the FBI is controlling your behavior by radio waves.

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Negative Symptoms of Schizophrenia ○ Negative schizophrenia symptoms are characterized by behavioral deficits ■ Avolition refers to a lack of energy and an inability to persist in routine activities ■ Alogia refers to a reduction in the amount or content of speech ■ Anhedonia is an inability to experience pleasure ■ Asociality refers to a severe impairment in social relationships including ● social isolation ● poor hygiene or grooming ● poor motivation

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Disorganization ○ Thought disorder which in extreme cases can lead to “word salad” and is often accompanied by behavioral disorganization. ○ Inappropriate affect.

Diagnosis and Cognitive Defects ●

Diagnosis ICD-10 Criteria ○ Thought echo, thought insertion or withdrawal, and thought broadcasting. ○ Delusions of control, influence, or passivity, clearly referred to body or limb movements or specific thoughts, actions, or sensations; delusional perception. ■ Hallucinatory voices giving running commentary on the patient’s behavior. ■ Persistent delusions of other kinds that are culturally inappropriate and completely impossible, such as religious or political identity, or superhuman powers and abilities (e.g. being able to control the weather, or being in communication with aliens from another world). ■ Persistent hallucinations in any modality. ■ Breaks in the train of thought, resulting in incoherence or irrelevant speech, or neologism. ■ Catatonic behavior, such as excitement, posturing, or waxy flexibility, negativity, mutism, and stupor. ■ “Negative” symptoms such as marked apathy, paucity of speech, and blurting or incongruity of emotional responses, usually resulting in social withdrawal and lowering of social performance.

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Schizophrenia Categories ○ Disorganized Type involves ■ Disorganized speech and flat affect ■ General disruption of behavior ○ Catatonic Type involves ■ Prolonged motor immobility states that alternate with periods of excitability ○ Paranoid Type involves ■ The presence of prominent delusions including persecution and grandiosity ○ Simple Type ■ The characteristics “negative” features of residual schizophrenia develop without being preceded by any overt psychotic symptoms.

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Cognitive Symptoms ○ Cognitive Impairments ■ People with schizophrenia may have: ● Poor concentration ● Poor memory ● Lack of initiative ● Slower movements and thinking ● Difficulties with problem solving ● Chances of developing schizophrenia increases as IQ decreases ■ 100% of people with schizophrenia may have some of these cognitive impairments

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Impact of Cognitive Deficits ○ May cause difficulties in everyday life than positive symptoms ○ People with these deficits may have trouble: ■ Understanding or remembering what people say ■ Finishing a job or chore ■ Remembering to do things Figure 1.3 Neuropsychological Profile of Schizophrenia

Introduction to the Neuroscience of the Disorder ●

Biological Mechanisms of Schizophrenia ○ Positive symptoms respond well to dopamine blocking agents. ○ Degree to which these “typical” antipsychotic medications bind to D2 receptors determines their potency in reducing symptoms. ○ D2 receptors located largely in caudate and n. accumbens. Explains why antipsychotics produce Parkinsonian side effects.

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The two systems of the brain neurotransmitter dopamine ○ The first dopamine system which is generated in the brain stem projects to the limbic system in the striatum. ■ Over activity in this system leads to delusions and hallucinations. ○ The second dopamine system which emerges from the same area of the brain stem, this system projects out the prefrontal cortex of the brain. ■ Reductions in dopamine in this system may lead to the negative symptoms of schizophrenia.

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Brain Pathology in Schizophrenia ○ Brains of people with schizophrenia show ■ Reduced volume of temporal and frontal cortex ■ Enlarged ventricles (reflecting loss of brain cells) ● For 12 of 15 twins, the schizophrenia twin could be identified by enlarged ventricles ■ Reduced metabolic activity within prefrontal cortex (frontal hypoactivation)

Figure 1.4 Human Brain Structure

Figure 1.5 Dopamine containing pathways in the human brain

Figure 1.6 Dopamine Theory of Schizophrenia

Figure 1.7 Cortex Cross-Sections...