Week 2 Flashcards
How is schizophrenia diagnosed?
Schizophrenia spectrum disorders, as the symptoms exists on a spectrum.
It is diagnosed using the DSM-5
It is considered a neurodevelopmental disorder - these are disorders where the nervous system is disturbed in some way.
What are some of the positive symptoms of schizophrenia?
HIDD
Hallucinations - experiencing a sensory experiences in the absence of an external stimuli. Can be of any 5 senses, auditory is most common.
Inappropriate affect - emotional response - crying from a joke
Delusions - Firmly held beliefs that are not grounded in reality. There is a greater power controlling their thoughts.
Disorganised speech/though - bizzare connections between ideas, trouble organising words into sentences others understand.
What are some of the negative symptoms of schizophrenia?
FAAAC
Flat affect - lack of emotional expression
Avolition - lack of motivation or interest in engaging in routine activities.
Alogia - poverty in speech
Anhedonia - loss of pleasure in activities previously enjoyed.
Catatonia - catatonic schizophrenia - motor abnormalities. Waxy flexibility.
DSM-5
The Diagnostic and Statistical Manual of the American Psychiatric Association .
What we currently use to match symptoms with a particular disorder to arrive at a diagnosis.
What evidence supports genetic factors in the development of schizophrenia?
Genetics play a large role in the development of schizophrenia. The more shared genetic material, the more likely schizophrenia can be developed.
Monozygotic twins
What evidence supports environmental factors in the development of schizophrenia?
Dizygotic twins - share the same amount of genetic material as siblings, but are more likely to develop schizophrenia than siblings, as they share the same prenatal environment, and are likely to share the same environment given their similarity in age.
Environmental risk factors of schizophrenia
Environment is thought to have an epigenetic effect - meaning environmental factors may turn genes off or on.
Environmental risk factors of schizophrenia
Environment is thought to have an epigenetic effect - meaning environmental factors may turn genes off or on.
- maternal stress, prenatal nutrition and prenatal infections
- Birth complications and childhood adversity
- Being born and raised in urban areas
- Exposure to toxins like marijuana or harmful alcohol use
- Highly stressful situations
Agonist
An agonist is drug that activates the receptor it binds to e.g. opium - stimulations
Creates a certain action
Produces a chemical reaction
Cocaine and amphetamines
Antagonist
A drug that binds to a receptor but does not activate it. The binding of an antagonist to a receptor can then block other substances from binding to, and activating, that receptor e.g. ip
Blocks the drug from activating
Opposes a certain action
Reduces stimulation
What is the dopamine theory of schizophrenia and how has it developed over time?
- Antipsychotic drugs had side effects that resembles Parkinson’s disease.
- Schizophrenia patients were given reserpine which had side effects that mimicked Parkinson’s
- The next discovery was that Parkinson’s is partly caused by low levels of dopamine.
- Stimulant drugs like cocaine and amphetamines, which are agonists, increase dopamine in the brain and in high doses can produce a state that closely resembles symptoms of schizophrenia.
In short, excess levels of dopamine cause schizophrenia, where as antipsychotic medication, such as reserpine reduces dopamine in the brain, subsequently reducing schizophrenia symptoms.
How has the treatment of schizophrenia developed over time?
- Indian snake root - reserpine - reduces dopamine in the brain.
- Chlorpromazine (claw-pro-ma-zeen) - didnt change the levels of dopamine in the brain. Antagonist - blocked the receptors in the brain. This changed the finding of the the dopamine theory of schizophrenia.
- Haloperidol an effective antipsychotic belonging to a group of drugs called butyrophenones
Chlorpromazine (claw-pro-ma-zeen)
Anti-psychotic Antagonist Blocks the D1 and D2 dopamine receptors From the group of drugs called phenothiazines (Feen-o-thigh-a-zeens)
Chlorpromazine (claw-pro-ma-zeen)
Anti-psychotic Antagonist Blocks the D1 and D2 dopamine receptors From the group of drugs called phenothiazines (Feen-o-thigh-a-zeens)
Haloperidol (hello-perri-doll)
Anti-psychotic Antagonist Only blocks D2 dopamine receptors From the group of drugs called butyrophenones (bu-tear-o-phen-ens)
Tardive dyskinesia
Tar-div dis-con-nee-sia
Involuntary movement within the body. Caused by antipsychotic medication. Can be irreversible. Known as extrapyramidal
Atypical antipsychotics
Second generation
Developed to improve issues associated with first generation medications
The first atypical antipsychotic to be developed - Clozapine D1, D4 and seotonin receptors
D2 D4
Glutamate and glycine
currently being studied investigating its role in schizophrenia
Monozygotic tiwns
1 egg, divides into 2
Identical Twins
Dizygotic Twins
Fraternal twins
2 separate eggs
Enlarged lateral ventricles
The larger ventricles along with the larger fissures often found in the brains of individuals suffering from schizophrenia signifies a loss in brain volume.
Loss of Brain Volume
Grey and white matter - found in pre-frontal cortex and temporal cortices, such as the hippocampus, amygdala, thalamus, anterior cingulate and nucleus accumbens.
Although brain volume reduces, the number of neurons does not, they are tightly packed together and it is believed the dendrites are compromised, the positive symptom of schizophrenia, disorganised thoughts and speech is thought to be a product of this. Dendritic branches and spines.
Aetiology
The cause of..or the history of
Polygenetic
Many genes associated with schizophrenia. ANd many of the same genes associated with major depression, autism, bipolar have also been linked to schizophrenia.
Synaptic pruning
The brains natural process of removing connections within the brain to make room for more useful connections as we get older. As seen in patients with schizophrenia , lack of connection in the brain as an increased elimination of synapses occurs.