Schizophrenia

Diagnosis & Classification of Schizophrenia

AO1

A chronic, severe mental disorder that affects the way a person thinks, acts, expresses emotions, & perceives reality.

Two diagnostic manuals; ICD-11 and DSM-5​

Positive symptoms - in addition to normal experiences e.g. ​​​​

hallucinations (unusual sensory experiences) & delusions (irrational false beliefs)

Psychosis is a mental state in which a person loses some contact with reality.​

Negative symptoms - a loss to normal experiences e.g. avoltion (lack of motivation) and speech poverty (reduction in speech)

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Neural Correlates of Schizophrenia

AO1

Abnormal levels of dopamine

Original hypothesis: High dopamine subcortex (hyperdopaminergia) = leads to hallucinations

Updated hypothesis: Added low levels of dopamine (hypodopaminergia) in pre frontal cortex = -ve symptoms

Enlarged ventricles (fluid filled pockets in the brain) - association with sz from brain scans

AO3

+ Amphetamines mimic symptoms and antipsychotics reduce them. Both work on DA.

- Sz like symptoms in rats using amphetamines but apomorphine inc. DA and no symptoms

- Post mortem and scans show higher Glutamate and several candidate genes linked to G

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Treatment: Drug therapies

AO1

Typical: dopamine antagonists (block dopamine receptors), 1950s, Chlorpromazine, sedation effect = helps to calm when hospitalised. Side effects - tardive dyskinesia, +ve symptoms, 1000mg max

Atypical: Newer (1970s), Clozapine, less side effects but agranulocytosis, works on DA & serotonin and glutamate receptors, improves mood, -ve and +ve symptoms, 450mg max

Risperidone, 1990s, developed due to agranulocytosis risk of Clozapine. Binds more strongly so lower doses = less side effects, 12mg max dose

AO3

+ Thornley - 13 trials (1121 ppts), chlorpromazine = less symptoms

-Studies = short term

- Side effects: tardive dyskinesia

- Should not work according to updated DA theory

- Ethical issues with sedation

Interactionist approach to Schizophrenia

AO1

Diathesis-stress model: vulnerability + trigger

Meehl's (1962) model: Original model suggested there was a schizogene = schizotaxia

Modern diathesis: Many genes involved, diathesis does not need to be genetic - could be trauma

Modern stress: Stress can be psychological (e.g. parenting) or biological (cannabis use x7 increased risk - linked to DA)

Treatment: Anti-psychotic medication & CBT to target biological and psychological elements

AO3

+ Tienari: adopted children with bio. sz mother. Higher sz with adoptive parents with high criticism, low empathy compared to controls.

- Original model: overly simplistic (Ripke 108 candidate genes)

+ Real world application: CBT & drug therapy most effective (Tarrier)

Issues with diagnosis

of Schizophrenia

AO1

Very complex disorder presents issues with diagnosis

Comorbity - 2 disorders at same time e.g. sz & bipolar - is sz a distinct disorder?

Symptom overlap - shares symptoms -issues with misdiagnosis & treatment

Culture bias - misrepresentation - males more often diagnosed

Gender bias - misrepresentation - men from afro-carribean heritage x9 more likely to be diagnosed

AO3

+ Good reliability: Osorio - +.97 inter rater & +.92 test retest

- Comorbidity: Buckley -depression 50%, substance abuse 47%

- Gender bias: Longernecker: males diagnosed 1.4:1 to females

- Culture bias: Pinto & Jones: Afro-Carribean men x9 more likely diagnosed

- Symptom overlap: hard to distinguish from bipolar

Psychological: Family Dysfunction

AO1

Schizophrenogenic mothers: psychodynamic, cold, rejecting and controlling (refrigerator mother). Leads to delusions. 

Double bind theory: Bateson, conflicting family communication (two conflicting messages received at the same time), when 'wrong' love withdrawn. Leads to disorganised thinking. 

Expressed emotion: Relapse explanation. Critical and hostile or emotional over involvement.  

AO3

+ Sz ppts more likely to have insecure attachments (Read)

- Lack of evidence for sz mother & double bind

- Social sensitivity: Parent blaming

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Treatments: CBT

AO1

CBTp: Modified CBT to target the psychosis

Helps identify & examine beliefs & offer alternative explanations for delusions

Therapist & patient work in collaboration & non confrontationallu

Educates patients of thoughts, feelings, behaviours

Normalisation - helps to understand its a continuum of 'normal' experience

Behavioural components e.g. social activity & relaxation

AO3 CBT

+ Jauhar: 34 studies of CBT for sz & significant effects

- Not a cure. Strong biological element. Drug therapy as well.

- Practical limitations e.g. psychosis leads to lack of self-awareness

Genetic Basis of Schizophrenia

AO1

Inherit a genetic predisposition

Twin studies: Gottesman 48% MZ twin, 17% DZ concordance rates

Many candidate genes

Polygenic with 108 genetic variations (Ripke)

Aetiologically heterogeneous: caused by different genes in different people

Mutation of paternal DNA: +ve correlation paternal age and sz - 2% risk when father is 50+

AO3

- Biologically deterministic

 - Incomplete explanation: 67% ppts past trauma - supports diathesis stress model

+ Real life application: genetic counselling ​

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Psychological: Cognitive explanations

AO1

Dysfunctional thought processing - lower levels of thought processing in ventral striatum = -ve symptoms

Cingulate and temporal gyri = +ve symptoms

Frith: Meta-representation dysfunction - cannot recognise thoughts as own = hallucinations

Frith: Central control dysfunction - Derailment of thoughts as cannot suppress automatic responses = speech poverty

AO3

+ Dysfunctional thought: sz ppts took x2 as long to complete Stroop task (Stirling)

- Does dysfunctional thoughts lead to sz or vice versa?

- Psychological or biological? Dysfunctional thoughts may be genetic in origin​​

Treatments:

Family Therapy

AO1

Aim for family to become a therapeutic alliance

Attempts to improve communication - reduce EE

Educate family about sz

Skill development: problem solving and communication

Coping strategies and warning of relapse - more supportive environment

Burbach's 7 stage model (1-2 identify resources, 3-4 identify unhelpful patterns, 5- 7 skills training and furture planning)

AO3

+ McFarlane: relapse rates reduced by 50-60%

+ Benefits the family - benefits beyond the patient: cost effective