Schizophrenia - Exam Review Flashcards
Positive symptoms
the introduction of new features to a person’s mind.
- includes hallucinations and delusions.
Delusions
false beliefs held in the face of compelling evidence to the contrary.
Categories of Delusions
- ) thought control
- ) self-reference
- ) self-importance
- ) guilt
Thought Control
Involves:
- thought insertion
- thought broadcasting
- thought withdrawal: (someone is taking thoughts out of your head).
Self-reference
Involves:
- Delusions of persecution: person feels punished by god/government.
- Delusions of reference: impression that an ordinary event has special meaning.
Self-importance
Involves:
- Grandiose delusions: person feels that they are Jesus, etc.
- Erotomanic delusions: thinking that someone important has a crush on them.
Guilt
Delusions of harming others: people thinking they have hurt others just by thought.
Hallucinations
sensory experiences without sensory stimulation.
Type of Hallucinations
- auditory.
- visual.
- olfactory.
- tactile.
- gustatory.
Bizarre vs non-bizarre delusion
bizarre –> belief in question cannot be true given what we know about the physical laws of the universe.
non-bizarre –> can be true within the limits of our physical laws, but has virtually no evidence.
Auditory hallucinations
- most common.
- activate primary auditory cortex which suggests that they may be subjectively experienced as a true sound stimulus.
Source monitoring confusion
says that hallucinations arise when a person mistakenly attributes internally generated precepts to an external origin.
Effect on behaviour
hallucinations and delusions often guide:
- isolation, self harm, and suicide.
Cognitive Symptoms
- ) disorganized thought: thought processes are non-linear.
- ) disorganized speech: jumping from one idea to the next.
Aspects of disorganized thought & speech
- ) Loose associations: joining words together that are only vaguely related in meaning.
- ) Clang associations: making words connections based on rhyming.
- ) Thought blocking: stopping mid sentence/thought.
- ) Neologisms: making new words while forming a sentence.
Negative Symptoms
the removal of certain features from a person’s mind & behaviour.
Include:
- social withdrawal
- anhedonia
- flat affect
Social withdrawal
disengagement from the social world.
Anhedonia
decrease in anticipated pleasure.
Flat affect
decreased expression of emotion.
Catatonia
Dysfunction in bodily movement. Can present as:
- agitated movement
- catatonic immobility (body remains still for a long time).
- waxy flexibility (body posture can be altered by someone else).
Prevalence & Course
- 1% of population develops schizophrenia.
- men have earlier onset.
- 1/3 recover completely, 1/3 recurring problems, 1/3 severely affected.
Diathesis of schizophrenia
- genetic: (50% chance for identical twins).
- experiential: (pre-natal exposure to maternal stress or virus).
Stress of schizophrenia
- life stressors –> poverty, discrimination, lack of social support.
- expressed emotion –> how family members react to diagnosis.
- drug use
Val/Met or Val/Val gene
If you have the val/met or val/val gene, marijuana use predicts vulnerability to developing schizophrenia.
Duration
symptoms must be present for at least 1 month.
Enlarged ventricles
- ventricles hold CSF.
- patients with schizophrenia have enlarged ventricles.
Enlarged ventricles are linked to:
Less brain matter in:
- thalamus
- striatum
- temporal lobes (hippocampus & auditory cortex).
Thalamus and schizophrenia
- smaller thalamus size predicts positive symptoms.
- damage to the thalamus can produce schizophrenia-like positive symptoms.
Sensory Gating
processes of filtering out irrelevant stimuli in the brain from environmental stimuli.
- thalamus is involved.
- people with schizophrenia have weaker filtering ability.
Dorsolateral prefrontal cortex (DLPFC)
Brain area involved in inhibiting unwanted cognition.
- schizophrenics have 20% lower dendritic spine (impaired) density in the DLPFC.
Sensory Filtering & Creativity
- strong link between deficit in P50 filtering and creativity.
- the same factor that seems to predispose people to schizophrenia, also underlies creativity.
How does urban living affect schizophrenia?
living in urban environments is associated with higher risk of developing schizophrenia.
