Lecture 9 - Psychosis

Shaw et al., 2020

found of all homocide convictions in England over 18 month period:

8% had contact with mental health services and less that 25% of these had diagnosis of SZ

people with SZ no more prone to criminal violence than the general public

Definition of Psychosis

inability to distinguish the internal experience of mind and external reality

Prevalence of Psychosis

1% of the population

Peak age of Onset for Psychosis

males = teens to mid-20s

female = teens to late-20s

What are the 5 Main Domains of Symptoms?

1. hallucinations

2. delusion

3. disorganised thoughts

4. disorganised behaviours

5. negative symptoms

Types of Hallucinations?

Auditory - sound

Visual - sight

Olfactory - smell

Gustatory - taste

Tactile - touch

Nociceptive - pain

Thermoceptive - temperature

Proprioceptive - movement

Definition of Delusions

fixed, false briefs that are maintained despite incontrovertible evidence to the contrary

Bizarre Delusions

clearly implausible

Non-bizarre Delusions

possible but no convincing evidence exists

Primary Delusions

incomprehensible and ambiguous (linked to SZ)

Secondary Delusions

understandable in terms of emotion state, circumstances etc

Persecutory Delusions

most common, the individual convinces they are being followed and will be harmed

Delusions of Infidelity

malignant jealousy in which individual has an overwhelming sense of entitlement

Referential Delusions

individual believes unsuspicious occurrences or media stories refer to them personally

Grandiose Delusions

the individual falsely believes in their own greatness or that they have supernatural powers

Erotomanic delusions

person falsely believes that another person is in love with them

Religious Delusions

delusions involving religious themes

Nihilistic Delusions

false belief that nothing exists

Somatic Delusions

focus on the preoccupation with appearance and bodily function

Delusional Parasitosis

false belief that they are infested with parasites

Disorganised thoughts

1. circumstantial thought

2. tangential thought

3. word salad

Disorganised Behaviours

unpredictable emotional responses

non-sensical actions

catatonic behaviour

Negative symptoms

decrease or loss in normal functioning

Avolition

loss of motivation

Alogia

poverty of speech

Anhedonia

loss of pleasure

Flat Affect

no or nearly no emotional expression

Psychomotor Retardation

slowing down of thought and reduction of physical movements

Catatonia

abnormalities in movement, speech, and behaviour

DSM-V characteristics of SZ

1. 2 or more present for significant (delusions, hallucinations, disorganised thoughts, catatonic behaviours, negative symptoms)

2. markedly lower level of functioning in one or more major areas

3. continuous for at least 6 months

4. schizoaffective disorder, depressive or bipolar disorder ruled out

5. not from substances

Prevalence of SZ

affects 24 million people or 1 in 300 people

What blurs the boundaries of SZ?

1. emotional situations

2. environmental cues

3. relatable feelings

4. role of religion

Gottesmann & Sheilds (1972)

aim - to investigate genetic influences on SZ by comparing concordance rates in MZ and DZ twins

found 42% in MZ and 9% in DZ

Heston (1966)

found greater risk of SZ in those with diagnosed SZ birth mothers, even though raised in another family

Cardno (2002)

investigated twins, one with SZ, schizoaffective or manic symptoms, for shared genetic risk factors

found significant genetic correlations between all 3 syndromes and there is a degree of overlap in the genes contributing

Dopamine Hypothesis

suggest disreguation with dopaminergic system

abnormal dopamine signalling centrally involves in psychotic symptoms

antipsychotics work by blocking dopamine d2 receptors, reducing overactive dopamine signalling

Biological Explanation

research suggests people can be more likely to experience SZ if their brain development was disrupted during pregnancy or in early childhood

risk = 5x greater

Psychological Stress

1. social factors

Treatment Approaches

1. oral anti-psychotic medication

2. psychological interventions (family interventions, psychoeducation and CBT)