1: Schizophrenia and Anxiety Flashcards
What percentage of the population have schizophrenia?
1%
At what age does schizophrenia usually present?
Late teens to mid 20s
What was dementia first described as?
Dementia praecox
Who was the first person to use the word schizophrenia and in what year?
Bleuler in 1908
What are some of the negative symptoms of schizophrenia?
Reduced speech
Difficulty with goal-orientated behaviour
Neglect of personal heigine
Flattened affect
What is flattened affect?
Reduced expression of emotion
What are some of the positive symptoms of schizophrenia?
Disorganised speech (A lack of logic and constantly changing topics)
Hallucinations (often auditory)
Delusions
Disorganised or catatonic behaviour
What fraction of people with schizophrenia have delusions?
4/5
What is the most common type of hallucination?
Auditory
What are the cognitive symptoms of schizophrenia?
Poor attention
Impaired verbal working memory
Impaired executive function - inflexiable thinking style
What are relapses and remissions in schizophrenia?
Symptoms go through cycles of improving and being more severe
What is the DSM criteria for diagnosis of schizophrenia?
2 or more symptoms present for at least 1 month and 1 present for 3 months
Ongoing signs of illness for 6 months
What disorders are often confused with schizophrenia?
Mood disorders (Depression or bipolar)
Substance abuse triggering an episode
brain damage
Huntington’s, parkinson’s and Alzheimer’s all have psychotic symptoms
if one identical twin has schizophrenia, what is the chance the other twin will also have it?
48%
What percentage of people with schizophrenia have no other relatives with it?
85%
How is the age of the father linked to the development of schizophrenia?
The older the father is when the baby is conceived, the higher the chance of schizophrenia
What is the interaction between genetics and environment?
They could trigger certain genes to be expressed
What neurodevelopmental factors contribute to schizophrenia?
Infections during pregnancy
traumatic birth
low birthweight
cannabis in teenage years
How is the brain structure of people with schizophreia different from others?
They have larger ventricles and less grey and white matter
How is over-pruning linked to schizophrenia?
Too much pruning in the prefrontal cortex meaning communication between different areas of the brain is disrupted
What neurotransmitters have been implicated in schizophrenia?
Dopamine
Glutamine
What is the dopamine hypothesis?
That dopamine levels are linked with schizophrenia
What evidence is there for the dopamine hypothesis?
Antipsychotic drugs work on dopamine receptors
PET scans show higher levels of dopamine synthesis in patients
High doses of drugs that increase dopamine cause psychotic symptoms
4/10 of the top associated genes are also linked to dopamine
What are typical antipsychotic drugs?
They act on D2 receptors and have many side effects such as tardive dyskinesia
What is tardive diskinesia?
Involuntary movements of the facial muscles
What are atypical antipsychotics?
They act on several classes of receptors including serotonin
Less side effects which are less severe
What are the limitations of the dopamine hypothesis?
1/3 of patients don’t respond to antipsychotics
The relationship between dopamine and negative symptoms is unclear
What is the glutamate hypothesis?
It’s due to a dysfunction of the NMDA glutamate receptor
What is the evidence for the glutamate hypothesis?
Ketamine was usedd as an anastetic and when patients came round, they had similar symptoms to schizophrenia
Mice bred with less receptrs have signs of schizophrenia
How many people are affected by anxiety at some point in their lives?
30%
What is generalised anxiety disorder?
Excessive worry, restlessness and trouble sleeping
What is a panic disorder?
Reoccuring, unexpected panic attacks
What is agoraphobia?
Where we excessively think our environment is unsafe
Such as not wanting to leave the house
How long do panic attacks usually last?
Less than 30 minutes
How is the sympathetic nervous system involved in panic attacks?
It triggers the fight or flight response
How is the parasympathetic nervou system involved in panic attacks?
It slows down the body and dampens the fight or flight response
How is the amygdala linked to anxiety?
It recieves sensory infomration from the cortex, thalamus and hippocampus and projects it to brain areas involved in emotional responses
Activated when we see fearful faces
In what part of the amygdala is sensory information processed?
The basolateral nucleus
The information is then passed to the central nucleus
How is the hippocampus linked to anxiety?
More concerned with factual information than emotion
Such as what the fear is paired with
How is the ventromedial prefrontal cortex linked to anxiety?
Involved in the enxinction of fear
How do benzodiazipines treat anxiety?
They enhance the activity of GABA
