Lecture 22- Psychosis Flashcards
Definition of psychosis
- Disorder of the mind
- The presence of hallucinations or delusions
- Describes symptoms, not a diagnosis in itself
Hallucinations
- Perception without a stimulus
- Can be in any sensory modality
- Visual hallucinations are usually organic (caused by problem with brain (SoL) or eyes)

Delusions
- Delusion – a fixed false belief, which is unshakeable.
- Outside of cultural norms.
Schizophrenia quick facts
- Patients with schizophrenia don’t have a split mind or personality
- Patients with schizophrenia are generally no more ‘dangerous’ than any other patient.
- 5% of violent crimes are committed by patients with severe mental illness, which means that 95% are committed by ‘normal people’!
First Rank Symptoms of schizophrenia
- Auditory hallucinations
- Passivity experiences
- Thought withdrawal, broadcast or insertion
- Delusional perceptions
- Somatic hallucinations
Positive symptoms of schizoprehnia
- Delusions, hallucinations, thought disorder, lack of insight
- Added symptoms
The positive symptoms are so called because they are thinking or behaviour that the person with schizophrenia did not have before they became ill and so can be thought of as being added to their psyche
Negative symptoms:
- Underactivity, low motivation, social withdrawal, emotional flattening,
- Self neglect
- Symptoms that take away from the patient
auditory hallunications

thought withdrawal, broadcast or insertion

passivity experiences

delusional perception

somatic hallucinations

All patients with Schizophrenia are different
- While patients with Schizophrenia might have the same cluster of symptoms e.g. delusions, hallucinations, absence of insight.
- How each patient experiences these symptoms will be completely different e.g.
- Delusions MI5 are following them
- Delusions witchcraft is being performed on them
- Delusions family are poisoning them
Pathophysiology of Schizophrenia
- Dopamine pathways
- Brain changes
- Limbic system
Dopamine (DA) theory of Schizophrenia
- Drugs e.g. amphetamines which cause the release of DA induces psychotic symptoms.
- All medications that antagonise DA receptors, help treat psychosis & those with the strongest affinity to D2 receptions are most clinically effective.
how many DA (dopaminergic) pathways in the brain?
4

4 dopamine pathways of the brain
- The Mesolimbic Pathway.
- The Mesocortical Pathway.
- The Nigrostriatal Pathway. …
- The Tuberoinfundibular (TI) Pathway.

Mesolimbic pathway
- From Ventral tegmental area to Limbic structures (amygdala, septal area, hippocampal formation) and Nucleus accumbens
- Thought to be overactive in schizophrenia

Mesocortical pathway
- From the ventral tegmental area to frontal cortex and cingulate cortex
- Thoughts to be underactive in schizophrenia

tuberoinfundibular pathways
from arcuate and periventricular nuclei of hypothalamus to the infundibular region of the hypothalamus

nigrostriatal parthways
from the substantia nigra pars compacta to striatum (caudate nucleus and putamen)





