11. Schizophrenia I

12 01neurLecture 11; Oct 10, 2013Schizophrenia I

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Schizophrenia Schizophrenia is classified as a psychotic

disorder.

Psychosis (from G. psyche mind/soul and -osis abnormal condition) means a loss of contact with reality.

Schizophrenia aects approximately 1/100 people in North America. The annual cost of schizophrenia in the US is estimated at around $60 billion, due largely to the cost of treatment and lost wages.

Schizophrenia is a common disease with severe consequences for patients and their loved ones, and for this reason, it is an area that has received a lot of attention from researchers.


Myths about schizophrenia1. MYTH: People who have schizophrenia are violent

and dangerous. FACT: Individuals who are being treated for

schizophrenia are not more violent than anyone else. For those living with untreated schizophrenia, they are the greatest danger to themselves - the greatest risk is self-harm or suicide.

2. MYTH: People who have schizophrenia have

multiple personalities. FACT: Schizophrenia is not the same as multiple

personality disorder (aka dissociative identity disorder.)

3. MYTH: People who have schizophrenia see things that arent there. FACT: Schizophrenia is characterized mostly by

auditory hallucinations (voices, etc.,.) Visual hallucinations are possible, but much less common.

4. MYTH: Schizophrenia is a rare condition. FACT: Schizophrenia affects 1/100 people.


Characteristics of schizophrenia The symptoms experienced by people with schizophrenia can be

divided into three basic groups.

Positive symptoms are symptoms that go beyond normally occurring experiences. E.g. hallucinations, delusions, paranoia.

Negative symptoms are characterized by a deficit or absence in a normal behavior. E.g. apathy, limited thought/speech, emotional and social withdrawal.

Cognitive symptoms (also called disorganized symptoms) are symptoms that are characterized by erratic changes in speech, motor behavior, and emotions. E.g. disorganized speech, inappropriate emotional reactions


Positive symptoms Delusions: irrational beliefs or paranoia that misrepresents reality.

Delusions of grandeur: i.e., belief that one is famous (such as Napoleon or Jesus Christ), or important in some special way (capable of ending world hunger, for example).

Delusions of persecution: i.e. when an individual believes that others are out to get him/her.

Erotomanic delusions: i.e. when an individual believes that another person (often a celebrity) is in love with him/her.

Delusions can be classified as bizarre if they are clearly implausible. i.e. Belief that an outside force has removed the individuals internal organs

and replaced them with those from someone else

Delusions can instead be non-bizarre, if they are somewhat plausible. i.e. Believing that the government is listening to the individuals phone calls

Delusions expressing a loss of control over mind and body are common. i.e. Belief that outside forces are inserting thoughts into ones mind, or that

ones body is being manipulated by some outside force.


Positive symptoms Hallucinations: the experience

of sensory events without any input from the surrounding environment. Hallucinations can involve any of the senses, but auditory hallucinations such as voices are the most common. Many hallucinations are simply

a running commentary of whats going on.

Others can be more sinister. Command hallucinations involve voices giving orders.


Negative symptoms Apathy: the inability to get started, to perform basic

day-to-day functions. This can lead to problems with hygiene, keeping a job,

and keeping a place to live.

Autism: refers to the tendency to keep to oneself and lose interest in other people or the surroundings. Note: autism here refers to a set of behaviors, not

comorbidity with autism the disorder.

Ambivalence: emotional and social withdrawal.

Anhedonia without pleasure (G.): indierence to activities that are typically considered to be pleasurable.

Aective flattening: the absence of visible emotions, facial expressions, and emotional inflections in speech. Approximately 25% of people with schizophrenia exhibit

a flat affect it is as though they are wearing an expressionless mask all the time.

Negative symptoms can lead to the neglect of basic life necessities such as employment and housing. As such, homelessness is common among people with schizophrenia.


Cognitive symptoms Disorganized speech: people with

schizophrenia have a confusing way of talking. They often jump about randomly from topic to

topic, or go off on illogical tangents.

Inappropriate aect: occasionally, people with schizophrenia display emotions that are inappropriate for the current situation. They may laugh or cry in situations that call for

neither.

Disorganized behavior: people with schizophrenia can show motor symptoms ranging from wild agitation to catatonic immobility. Catatonic patients seem frozen in place, but may

display waxy flexibility.


A video

http://www.youtube.com/watch?v=gGnl8dqEoPQ


DSM-5 diagnostic criteria Key points:

Individual must have at least one of: delusions, hallucinations, or disorganized speech.

Diminished level of function.

Long-lasting symptoms.

Not due to drugs or some other medical condition.


History The condition historically known simply as

madness or lunacy likely corresponds to what we now call schizophrenia.

Emil Kraeplin (1856-1926) was the first to thoroughly define the symptoms of schizophrenia, combing several elements of insanity into one disorder. Catatonia, hebephrenia (silly and immature

emotionality), and paranoia had previously been as separate disorders.

He also distinguished schizophrenia from manic-depression (which we now call bipolar disorder)

Kraeplin called schizophrenia dementia praecox premature dementia (L.) because the disorder usually appears in late adolescence.

Emil Kraeplin (1856-1926)


History Eugen Bleuler (1857-1939) introduced the term

schizophrenia, replacing Kraeplins dementia praecox. This name change is important, because it shows

that Bleuler believed that the core problem was not premature aging of the brain.

The word schizophrenia means split mind (G.), and this comes from Bleulers belief in the breaking of associative threads the destruction of forces that connect one function to the next.

In other words, the various elements of the individuals mind become disconnected from each other. Thoughts no longer have any logical connection to each other, or to reality in general.

Unfortunately, the concept of split mind has lead to the popular but incorrect use of schizophrenia to refer to split/multiple personalities.

Eugen Bleuler (1857-1939)


Development Schizophrenia is usually diagnosed in

late adolescence or early adulthood. It strikes right as people enter the world

and begin to gain independence, it is a cruel surprise that deprives people of the chance of a normal life.

There is usually a lag of 1-2 years between the first onset of symptoms and diagnosis.

In 85% of people, full-blown schizophrenia is preceded by a prodromal stage a 1-2 year period where subdued symptoms begin to appear. Magical thinking, minor illusions (feeling

of a presence when one is alone, etc.,), and ideas of reference are common prodromal symptoms.

Mental illnesses like schizophrenia often appear during university. The stress of moving, school, and possible drug/alcohol abuse probably makes it worse.


Development and prognosis Complete remission is rare: most people (~78%) being

treated for schizophrenia go through a pattern of relapse and recovery.

The prognosis for schizophrenia is poorer than for most other disorders, but recovery/remission is more likely given the following factors: Good social adjustment prior to onset of schizophrenia. A low proportion of negative symptoms. A good social support system for patients.

The symptoms of schizophrenia may decrease with age, or at least level out.


Development and prognosis

Illustration from Barlow & Durand, Abnormal Psychology, 6th ed. Wadsworth, 2012


Etiology - genetics There is clear evidence for a genetic link

to schizophrenia. This can be shown by looking at how

the relative risk of developing the illness changes depending on whether other people in ones family have schizophrenia.

Monozygotic (identical) twins share 100% of their genes. Therefore, if schizophrenia was 100%

caused by genetics, both twins would always have schizophrenia.

In reality, the risk is only 48%.

Dizygotic (fraternal) twins only share 50% of their genes. If schizophrenia was 100% genetic,

then youd expect 50% of fraternal twins to have schizophrenia if the other does.



Endophenotypes Endophenotypes are subtle markers of disorder-related genes

that appear in people before overt symptoms.

People with schizophrenia have deficient smooth-pursuit eye tracking. Their relatives also show deficiencies.



Endophenotypes Pre-pulse inhibition (PPI)

happens when a startling stimulus of some kind (a pulse) is preceded by a warning pre-pulse.

In healthy people, a pre-pulse warning reduces their startle response. This does not happen in people with schizophrenia, and it is also reduced in their relatives.

Antipsychotic drugs increase PPI in people with schizophrenia.

People with schizophrenia have impaired pre-pulse inhibition. This can also be used as an animal measure of schizophrenic-like symptoms.


Etiology How can it be that even if you possess

100% of your twins schizophrenic genes, your odds of developing the disorder are only 48%?

Genetics are somewhat like a loaded gun. Having bad genes does not guarantee developing the disorder, but it certainly raises the risk.

Something else must happen during life to trigger the illness


Etiology perinatal factors There is evidence that problems before

and shortly after birth (the perinatal period) can increase the risk of developing schizophrenia.

Fetal exposure to influenza and other virus-like diseases may subtly damage the fetal brain in a way that causes the symptoms of schizophrenia later in life.

Pregnancy and delivery complications are also correlated with the development of schizophrenia.


Etiology - stress Stress seems to be a contributing factor in the development

of schizophrenia in individuals who are susceptible.

Numerous studies have shown that diagnoses of schizophrenia are often preceded by a stressful life event. Anecdotal evidence seems in favor of this as well. Schizophrenia

often appears in the midst of the stressful transition to independent living that young adults undergo.

There is also evidence that people with schizophrenia experience stressors in a dierent way. A study of an earthquake in California found that people with

schizophrenia were more likely to react to this stressor with low self-esteem and avoidant coping styles (not thinking of the problem, giving up).

Stress and genetics interact. Having a risky genetic background may be a loaded gun, but stress may pull the trigger.

11. Schizophrenia I

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