Anxiety Disorders and Schizophrenia Flashcards
What is the biopsychosocial approach?
Our biology, psychology, and social context interact in order to create a disease.
What contributes to our biology that can affect our health?
- Gender
- Physical illness
- Disability
- Genetic vulnerability
- Immune function
- Neurochemistry
- Stress reactivity
- Medication effects
What contributes to our psychology that affects our health?
- Learning/memory
- Attitudes/beliefs
- Personality
- Behaviours
- Emotions
- Coping Skills
- Past Trauma
What contributes to our social context that affects health?
- Social Supports
- Family background
- Cultural traditions
- Socioeconomic Status
- Education
What is the lifetime prevalence of schizophrenia?
1%
When is schizophrenia most likely to manifest?
Late teens to early 20s
What and when was schizophrenia first described as?
1893 - Dementia Praecox
Later was defined as schizophrenia in 1908.
What are positive symptoms of schizophrenia?
Involve the presence of symptoms:
- Delusions
- Hallucinations
- Disorganised speech (jumping between topics or nonsense sentences)
- Grossly disorganised or catatonic behaviour such as rocking
What are negative symptoms of schizophrenia?
Involve the absence of response:
- Reduced expression of emotion (show no interest in anything)
- Poverty of speech
- Difficulty initiating goal directed behaviour
- Neglect of personal hygiene
What is a psychotic episode?
A period of intense positive symptoms
What are some examples of cognitive symptoms?
- Poor ability to maintain attention
- Impaired verbal working memory
- Inflexible thinking style - difficulty in adapting
What is the difference between the presence of positive/negative symptoms vs cognitive symptoms?
Positive and negative symptoms improve and worsen in cycles of relapse and remission, whereas cognitive symptoms are relatively stable over the course of the illness.
What is the DSM-V criteria for schizophrenia?
Two or more of the following symptoms must be present for at least 1 month and one of which must be one of the first 3 listed:
- Delusions
- Hallucinations
- Disorganised Speech
- Disorganised or catatonic behaviour
- Negative symptoms
Also, social/occupational dysfunction and continuous signs of illness for at least 6 months with at least 1 month of active symptoms.
What disorders often have similar symptoms to schizophrenia?
- Mood disorders such as depression or bipolar with psychotic features
- Substance abuse eg. cocaine or LSD
- Brain damage
- Huntingtons, parkinsons, alzheimers
What are the causes of schizophrenia?
Often an interaction between genes and the environment but specifically:
- Genetics
- Neurodevelopment
- Brain abnormalities
- Neurotransmitters
What is the relationship between genetics and schizophrenia?
There is evidence for schizophrenia to be based down with genetics. For example, someone whose parent is schizophrenic is 13 times more likely to develop the disease and someone with an identical twin with schizophrenia has a 48% chance of developing it. However, it is not always the case as 85% of those with schizophrenia have no first degree relative with the illness.
Which genes are involved in schizophrenia?
A large number of high risk gnes have been identified (more than 100), with some overlapping with other disorders like autism.
Specifically the dopamine receptor (D2) gene - links to treatment but explains less than half of genetic variance.
What do gene mutations have to do with schizophrenia?
Increased paternal age of conception can lead to gene mutations that lead to increased risk of schizophrenia. Is an explanation for how the lifetime prevalence is still 1% despite the low rates of reproductivity and earlier death rates.
What is the gene-environment interaction in schizophrenia?
Some genotypes are more likely to develop the disease when exposed to certain environments. Eg. if someone has a parent with schizophrenia and also has a dysfunctional family they are more likely to get the disease.
What neurodevleopmental factors can cause schizophrenia?
- Prenatal factors (infections during pregnancy, low birth weight etc) might affect neurodevelopment
- Cannabis use can increase risk of schizophrenia (unsure of causality however)
What brain abnormalities are found in schizophrenia?
- Larger than average ventricles
- Less grey matter
- Less white matter (loss of myelin sheath)
- Less brain connectivity (synaptic over-pruning)
- Reduced corpus callosum volume
Not sure of cause and effect as these areas worsen during disease.
What neurotransmitters are linked to schizophrenia?
Dopamine and glutamine systems
What is the dopamine hypothesis?
Neurones release dopamine faster than average which results in excess activity.
Evidence?
- Antipsychotic drugs act on dopamine receptors
- Dopaminergic recreational drugs create symptoms similar to schizophrenia eg. hallucinations in cocaine
How do neuroleptic (Typical) drugs work to treat symptoms in schizophrenia?
Block D2 receptors which lead to improved positive symptoms (it reduces these symptoms).
Side effects:
More than 80% of binding to d2 receptors can result in extrapyramidal symptoms (eg. rigidity and motor restlessness).
